MR. JUSTICE FIELD delivered the opinion of the Court.
The Mississippi River flows between the States of Iowa and
Illinois. It is a navigable stream, and constitutes the boundary
between the two states, and the controversy between them is as to
the position of the line between its banks or shores which
separates the jurisdiction of the two states for the purpose of
taxation and other purposes of government.
The complainant, the State of Iowa, contends that for taxation
and for all other purposes, the boundary line is the middle of the
main body of the river, taking the middle line between its banks or
shores without regard to the "steamboat channel," as it is termed,
or deepest part of the stream, and that to determine the banks or
shores, the measurements must be taken when the water is in its
natural or ordinary stage, neither swollen by floods nor shrunk by
droughts.
On the other hand, the defendant, the State of Illinois, claims
that, for taxation and all other purposes, its jurisdiction extends
to the middle of "the steamboat channel" of the river, wherever
that may be, whether on its east or west bank, the channel upon
which commerce on the river by steamboats or other vessels is
usually conducted and which for that reason is sometimes designated
as "the channel of commerce."
The State of Iowa in its bill alleges that prior to and at the
time of the treaty between England, France, and Spain in 1763, 3
Jenkinson's Treaties 177, the territory now comprising the State of
Iowa was under the dominion of France, and the territory now
comprising the State of Illinois was under the dominion of Great
Britain, and that, by the treaty named, the middle of the River
Mississippi was made the boundary line between the British and
French possessions in North America.
That by the Treaty of Paris between Great Britain and the United
States, which was concluded September 3, 1783, 3 Jenkinson's
Treaties 410, Art. II, and 8 Stat. 80, the territory comprising the
State of Illinois passed to the United States
Page 147 U.S. 3
and that by the purchase of Louisiana from France, under the
treaty of 1803, 8 Stat. 208, the territory comprising the State of
Iowa passed to the United States.
That the boundary between the territory comprising the States of
Illinois and Iowa remained the middle of the River Mississippi, as
fixed by the treaty of 1763.
That by the Act of Congress of April 18, 1818, known as the "Act
Enabling the Illinois to Form a state constitution," 3 Stat. 428,
the northern and western boundaries of Illinois were defined as
follows: starting in the middle of Lake Michigan at north latitude
forty-two degrees and thirty minutes, "thence west to the middle of
the Mississippi River, and thence down along the middle of that
river to its confluence with the Ohio River," and that the
Constitutions of Illinois of 1818, 1848, and 1870 defined the
boundaries in the same way.
And the bill further alleges that the State of Illinois and its
several municipalities bordering on the Mississippi River claim the
right to assess and do assess and tax, as in Illinois, all bridges
and other structures in the river from the Illinois shore to the
middle of the steamboat channel, or channel of the river usually
traversed by steam and other crafts in carrying the commerce of the
river, whether such channel is east or west of the middle of the
main body or arm of the river, and that they thus assess and tax,
as in that state, the bridge of the Keokuk and Hamilton Bridge
Company across the river from Keokuk, Iowa, to Island No. 4, in
Hancock County, Illinois, from the west shore of the island
westward 2,462 feet to the east end of the draw of the bridge, and
to a point not over 580 feet east from the Iowa shore of the river
and 941 feet west of the middle of the main arm or body of the
river at that point.
That the steamboat channel, or channel of the river where boats
ordinarily run in carrying the commerce of the river, varies from
side to side of the river, sometimes being next to the Illinois
shore and then next to the Iowa shore, and at most points in the
river shifting from place to place as the sands of its bed are
changed by the current of the water; that at the point of the
Keokuk and Hamilton Bridge, mentioned,
Page 147 U.S. 4
the river bed is rock, and not subject to much change; that at
that point, were it not for the bridge, the middle of the steamboat
channel would be, and was before the bridge was erected, fully 300
feet east of the east end of the draw in the bridge, or 880 feet
from the Iowa shore of the river and 2,162 feet from the shore of
the river in Illinois on Island No. 4; that at places in the river,
there are two or more channels equally accessible and useful for
navigation by steamboats and other crafts carrying the commerce of
the river, and that at the Keokuk and Hamilton Bridge, the channel
used by steamboats is partly artificial, constructed by excavation
of rock from the river bed to facilitate the approach to the lock
of the United States canal immediately north of the bridge.
That the State of Iowa claims the right to tax all bridges
across the river to the middle thereof, and does tax the Keokuk and
Hamilton Bridge to its middle between the east and west abutments
thereof -- that is, the west approach and abutment, 200 feet, and
1,096 feet of the bridge proper -- thereby treating, for
convenience of taxation, the middle of the bridge between abutments
as the middle of the river at that point, but which is in fact 225
feet less than one-half the distance across the main arm or body of
the river at that point.
That the State of Illinois and its municipalities assess and
tax, as in that state, 716 feet of the bridge actually assessed and
taxed in Iowa, and 225 feet of the bridge, in addition thereto,
located in Iowa, but not taxed in that state.
That the Keokuk and Hamilton Bridge Company, owner of the Keokuk
and Hamilton Bridge, is a corporation of both of said states,
consolidated, and complains of such double taxation.
That litigation is now pending over such taxation, and is liable
at any time to arise over the taxation of any of the other bridges
across the river between the said states, now nine in number.
To the end, therefore, that the line between the states may be
definitely fixed by the only court having jurisdiction to do so,
the complainant prays that this Court will take jurisdiction of
this bill and that the State of Illinois be summoned and
Page 147 U.S. 5
requested to answer it, waiving such answer's being on oath, and
that, upon the final hearing, this Court will definitely settle the
boundary between the states at the said several bridges.
To this bill the State of Illinois appeared by its Attorney
General and filed its answer, which denied that the boundary line
between the states of Iowa and Illinois is the middle of the
Mississippi River and insisted that it is the middle of the
steamboat channel, or channel commonly used by boats in carrying
the commerce of the river, whether east or west of the middle of
the river. It admitted that the state and its municipalities
claimed the right to tax and did tax bridges and other structures
in the river to the middle of the steamboat channel or channel of
commerce, whether such channel was east or west of the middle of
the main body or arm of the river, and did assess and tax the
Keokuk and Hamilton Bridge to its draw, and west of the middle of
the main body or arm of the river, and that the steamboat channel
or channel of commerce is first near one shore, and then near the
other, and at other places nearly across the river. But it denied
the right of the State of Iowa to tax the bridges mentioned
crossing the Mississippi River to any point east of the middle of
the steamboat channel or channel of commerce of that river.
To the answer a replication was filed by the State of Iowa.
At the time of filing its answer, the State of Illinois filed
also its cross-bill, in which it alleges that there exist nine
bridges across the Mississippi River between the states, the most
southern of which is the Keokuk and Hamilton Railroad bridge, and
the most northern the Dunlieth and Dubuque Bridge Company's
railroad bridge.
That for the purposes of taxation, the State of Illinois and its
municipalities claim the right to assess and tax the respective
bridges to the middle of the channel of commerce or steamboat
channel -- that is, the channel usually used by steamboats and
other crafts navigating the river -- and that on the part of the
State of Iowa and its municipalities, it is claimed that each state
has the right to assess and tax to the middle of the main arm or
body of the river, regardless of where the channel of commerce or
steamboat channel may be.
Page 147 U.S. 6
That the Supreme Court of Iowa, in the case of Dunlieth and
D. B. Co. v. County of Dubuque, 55 Ia. 558, held that the
authorities in Iowa have the right to tax such structures to the
middle of the main arm or body of the stream, and no further,
though at the point where such structure is situated the channel or
part of the river followed by steamboat men in navigating the river
is far east of the middle of such main body of the stream.
That, following the decision in that case, the authorities in
Iowa assess and tax such structures to the middle of the main body
of the river.
That at the point of the location of the Keokuk and Hamilton
Bridge, the main body of the river, before the construction of the
bridge, was between the Iowa shore at Keokuk, Lee County, Iowa, and
the west shore of Island No. 4, located in the City of Hamilton,
Hancock County, Illinois, a breadth of about 3,042 feet; that in
constructing the bridge, a solid approach is extended from the
shore at Keokuk into the river 200 feet, and from the shore on
Island No. 4, in Illinois, about 700 feet, and the main body of the
river confined between the abutments to the bridge 2,192 feet
apart, and the bridge consists of the east and west abutments,
eleven piers, a draw next to the west or Iowa abutment of 380 feet,
and ten spans, together 1,812 feet.
That the middle of the steamboat channel, or that part of the
river usually traversed by steamboat men in navigating the river,
is at or near the east end of the draw or pivot span, about 380
feet from the west abutment and 1,812 feet from the east
abutment.
That the assessor in Illinois, in assessing the bridge, values
the bridge to the east end of the draw, and assesses the same
against that part of the bridge in Illinois, and the authorities in
Iowa value and assess the bridge to the middle thereof, 1,096 feet
east from the west abutment, as in the State of Iowa; that thereby
716 feet of the bridge are valued and assessed both in Illinois and
Iowa; that litigation is now pending in the lower courts between
the bridge company and the authorities over the assessments, and
that the same
Page 147 U.S. 7
trouble and complications are liable to arise over the
assessment of any other of the bridges.
To the end, therefore, that the boundary line between the States
of Illinois and Iowa at said several bridges may be defined and
settled, the State of Illinois prays that the State of Iowa be made
defendant to this cross-bill and required to answer it, and that
upon the final hearing, the court will define and establish at each
of the bridges the boundary lines between the States of Illinois
and Iowa, to which points the respective states may tax. To this
cross-bill the defendant, the State of Iowa, answered, admitting
the existence of nine bridges across the Mississippi River, where
it forms the boundary between the States of Illinois and Iowa, and
that the State of Illinois and its several municipalities bordering
upon the river claim the right to tax said bridges from the
Illinois shore of the river to the middle of the channel of
commerce or steamboat channel, and that the State of Iowa and its
municipalities bordering on the river claim the right to tax, and
do tax, the several bridges to the middle of the main arm or body
of the river, regardless of where the channel of commerce or
steamboat channe1 -- that is, that part of the river usually
traversed by steam or other vessels carrying the commerce of the
river -- may be. It therefore prays that upon the final hearing,
the boundary lines between the two states may be established to
which the respective states may tax.
By setting down the case for hearing on the bill, answer, and
replication, without taking any testimony, and on the cross-bill
and the answer to it, all the facts alleged in the answer to the
original bill, as well as those alleged in the cross-bill and not
denied in the answer, are thereby admitted.
When a navigable river constitutes the boundary between two
independent states, the line defining the point at which the
jurisdiction of the two separates is well established to be the
middle of the main channel of the stream. The interest of each
state in the navigation of the river admits of no other line. The
preservation by each of its equal right in the navigation of the
stream is the subject of paramount interest. It
Page 147 U.S. 8
is therefore laid down in all the recognized treatises on
international law of modern times that the middle of the channel of
the stream marks the true boundary between the adjoining states up
to which each state will on its side exercise jurisdiction. In
international law, therefore, and by the usage of European nations,
the term "middle of the stream," as applied to a navigable river,
is the same as the middle of the channel of such stream, and in
that sense the terms are used in the treaty of peace between Great
Britain, France, and Spain, concluded at Paris in 1763. By the
language, "a line drawn along the middle of the River Mississippi
from its source to the river Iberville," as there used, is meant
along the middle of the channel of the River Mississippi. Thus,
Wheaton, in his Elements of International Law, (8th ed. § 192),
says:
"Where a navigable river forms the boundary of conterminous
states, the middle of the channel or thalweg is generally
taken as the line of separation between the two states, the
presumption of law being that the right of navigation is common to
both; but this presumption may be destroyed by actual proof of
prior occupancy and long undisturbed possession, giving to one of
the riparian proprietors the exclusive title to the entire
river."
And in § 202, while thus stating the rule as to the boundary
line of the Mississippi River being the middle of the channel,
states that the channel is remarkably winding, "crossing and
recrossing perpetually from one side to the other of the general
bed of the river."
Mr. Creasy, in his First Platform on International Law, § 231,
p. 222, expresses the same doctrine. He says:
"It has been stated that where a navigable river separates
neighboring states, the thalweg, or middle of the navigable
channel, forms the line of separation. Formerly a line drawn along
the middle of the water, the medium filum aquae, was
regarded as the boundary line, and still will be regarded prima
facie as the boundary line, except as to those parts of the
river as to which it can be proved that the vessels which navigate
those parts keep their course habitually along some
Page 147 U.S. 9
channel different from the medium filum. When this is
the case, the middle of the channel of traffic is now considered to
be the line of demarcation."
Mr. Creasy also refers to the language of Dr. Twiss on the same
subject, who observes that
"Grotius and Vattel speak of the middle of the river as the line
of demarcation between two jurisdictions, but that modern
publicists and statesmen prefer the more accurate and more
equitable boundary of the navigable mid-channel. If there be more
than one channel of a river, the deepest channel is regarded as the
navigable mid-channel for the purpose of territorial demarcation,
and the boundary line will be the line drawn along the surface of
the stream corresponding to the line of deepest depression of its
bed. The islands on either side of the mid-channel are regarded as
appendages to either bank and if they have once been taken
possession of by the nation to whose bank they are appendant, a
change in the mid-channel of the river will not operate to deprive
the nation of its possession, although the water frontier line will
follow the change of the mid-channel."
Halleck, in his Treatise on International Law, c. 6, § 23, is to
the same effect. He says:
"Where the river not only separates the conterminous states, but
also their territorial jurisdictions, the thalweg, or
middle channel, forms the line of separation through the bays and
estuaries through which the waters of the river flow into the sea.
As a general rule, this line runs through the middle of the deepest
channel although it may divide the river and its estuaries into two
very unequal parts. But the deeper channel may be less suited or
totally unfit for the purposes of navigation, in which case the
dividing line would be in the middle of the one which is best
suited and ordinarily used for that object."
Woolsey, in his International Law, § 58, repeats the same
doctrine, and says:
"Where a navigable river forms the boundary between two states,
both are presumed to have free use of it, and the dividing line
will run in the middle of the channel unless the contrary is shown
by long occupancy or agreement of the parties. If a river changes
its bed, the line through the old channel continues, but the
equitable right to the free
Page 147 U.S. 10
use of the stream seems to belong, as before, to the state whose
territory the river has forsaken."
The middle of the channel of a navigable river between
independent states is taken as the true boundary line, from the
obvious reason that the right of navigation is presumed to be
common to both in the absence of a special convention between the
neighboring states or long use of a different line equivalent to
such a convention.
Phillimore, in his Commentaries on International Law, in the
chapter upon "Acquisitions" (c. xii), speaks of decisions upon the
law of property as incident to neighborhood proceeding upon the
principle that "mid-channel" is the line of demarcation between the
neighbors. Volume 1, 239.
The reason and necessity of the rule of international law as to
the mid-channel's being the true boundary line of a navigable river
separating independent states may not be as cogent in this country,
where neighboring states are under the same general government, as
in Europe, yet the same rule will be held to obtain unless changed
by statute or usage of so great a length of time as to have
acquired the force of law.
As we have stated, in international law and by the usage of
European nations, the terms "middle of the stream" and
"mid-channel" of a navigable river are synonymous and
interchangeably used. The Enabling Act of April 18, 1818, 3 Stat.
428, p. 545, under which Illinois adopted a constitution and became
a state and was admitted into the union, made the middle of the
Mississippi River the western boundary of the state. The
Enabling Act of March 6, 1820, 3 Stat. c. 22, § 2, p. 545, under
which Missouri became a state and was admitted into the union, made
the middle of the main channel of the Mississippi River
the eastern boundary so far as its boundary was conterminous with
the western boundary of Illinois. The Enabling Act of August 6,
1846, 9 Stat. 56, c. 89, under which Wisconsin adopted a
constitution and became a state and was admitted into the union,
gives the western boundary of that state, after reaching the River
St. Croix, as follows
"Thence down the main channel of said river to the Mississippi,
thence down the center of the main
Page 147 U.S. 11
channel of that [Mississippi] river to the northwest corner of
the State of Illinois."
The northwest corner of the State of Illinois must therefore be
in the middle of the main channel of the river which forms a
portion of its western boundary. It is very evident that these
terms, "middle of the Mississippi River," and "middle of the main
channel of the Mississippi River," and "the center of the main
channel of that river," as thus used, are synonymous. It is not at
all likely that the Congress of the United States intended that
those terms, as applied to the Mississippi River separating
Illinois and Iowa, should have a different meaning when applied to
the Mississippi River separating Illinois from Missouri, or a
different meaning when used as descriptive of a portion of the
western boundary of Wisconsin. They were evidently used as
signifying the same thing.
The question involved in this case has been elaborately
considered, both by the Supreme Court of Iowa and the Supreme Court
of Illinois, in cases relating to the assessment and taxation of
bridges crossing the Mississippi River, as to the point to which
the jurisdiction of each state for taxation extends, and they
differed in their conclusions. In Dunlieth and Dubuque Bridge
Company v. County of Dubuque, 55 Ia. 558, 564, the Supreme
Court of Iowa, after observing that the act of Congress admitting
Iowa into the union, and the Constitution of Iowa in its preamble,
declare that the eastern boundary of the state shall be "the middle
of the main channel of Mississippi River," proceeds to inquire what
line is understood by those words, "middle of the main channel."
The defendant maintained that the deep water of the stream used in
the navigation of the river was meant, while the plaintiff insisted
that the words described the bed in which the stream of the river
flows -- that is, the bed over which the water flows from bank to
bank. The court thought that the words, when applied to rivers
generally, without the purpose of describing their currents or
navigable characters, always bore the latter signification,
observing that this was their primary meaning, and was of opinion
that they were used in that sense in the act of Congress admitting
the state into the
Page 147 U.S. 12
union and in the Constitution of Iowa. In support of this view,
the court referred to the changing character of the currents of the
river followed by vessels caused by the shifting nature of the sand
bars found in the river. "The course of navigation," it said,
"which follows what boatmen call the 'channel,' is extremely
sinuous, and often changing, and is unknown except to experienced
navigators. On the other hand, the bed of the main river,
designated by the word 'channel,' used in its primary sense, is the
great body of water flowing down the stream. It is broad and well
defined by islands or the main shore. It cannot be possible that
Congress and the people of the state, in describing its boundary,
used the word 'channel' to describe the sinuous, obscure, and
changing line of navigation, rather than the broad and distinctly
defined bed of the main river. The center of this riverbed channel
may be readily determined, while the center of the navigable
channel often could not be known with certainty. The first is a fit
boundary line of a state. The second cannot be."
In Buttenuth v. St. Louis Bridge Co., 123 Ill. 535, the
Supreme Court of Illinois reached a different conclusion after an
elaborate consideration of the same question. That was a case where
an alleged overestimate was made of a bridge crossing the
Mississippi River at St. Louis, and the question discussed was how
far did the jurisdiction of Illinois extend over the river? After
observing that when a river is a boundary between states, as is the
Mississippi between Illinois and Missouri, it is the main -- the
permanent -- river which constitutes the boundary, and not that
part which flows in seasons of high water and is dry at others, the
court proceeds, treating the Mississippi River as a common boundary
between the States of Illinois and Missouri, to inquire the meaning
of the term, "middle of the Mississippi River," used in the
Enabling Act of Congress and in the Constitution, defining the
boundaries of the State of Illinois. It answers the inquiry by
observing that the word "channel" is used as indicating "the space
within which ships can and usually do pass," and says
"It is apprehended it is in this sense the expressions
'middle
Page 147 U.S. 13
of the river,' 'middle of the main channel,' 'mid-channel,'
'middle thread of the channel,' are used in Enabling Acts of
Congress and in state constitutions establishing state boundaries.
It is the free navigation of the river -- when such river
constitutes a common boundary, that part on which boats can and do
pass, sometimes called 'nature's pathway' -- that states demand
shall be secured to them. When a river, navigable in fact, is taken
or agreed upon as the boundary between two nations or states, the
utility of the main channel, or -- what is the same thing -- the
navigable part of the river, is too great to admit a supposition
that either state intended to surrender to the state or nation
occupying the opposite shore the whole of the principal channel or
highway for vessels, and thus debar its own vessels the right of
passing to and fro for purposes of defense or commerce. That would
be to surrender all, or at least the most valuable part of, such
river boundary, for the purposes of commerce or other purposes
deemed of great value, to independent states or nations."
The opinions in both of these cases are able, and present in the
strongest terms the different views as to the line of jurisdiction
between neighboring states, separated by a navigable stream; but we
are of opinion that the controlling consideration in this matter is
that which preserves to each state equality in the right of
navigation in the river. We therefore hold, in accordance with this
view, that the true line in navigable rivers between the states of
the union which separates the jurisdiction of one from the other is
the middle of the main channel of the river. Thus, the jurisdiction
of each state extends to the thread of the stream -- that is, to
the "mid-channel," and if there be several channels, to the middle
of the principal one, or, rather, the one usually followed.
It is therefore ordered, adjudged, and declared that the
boundary line between the State of a Iowa and the State of Illinois
is the middle of the main navigable channel of the Mississippi
River, and, as the counsel of the two states both desire that this
boundary line be established at the places where the several
bridges mentioned in the pleadings -- nine in number -- cross the
Mississippi River, it is further ordered
Page 147 U.S. 14
that a commission be appointed to ascertain and designate at
said places the boundary line between the two states, such
commission, consisting of three competent persons, to be named by
the court upon suggestion of counsel and be required to make the
proper examination, and to delineate on maps prepared for that
purpose the true line as determined by this Court, and report the
same to the court for its further action.