U.S. Supreme Court
Iowa v. Illinois, 147 U.S. 1 (1893)
Iowa v. Illinois
No. 5, Original
Submitted November 28, 1892
Decided January 3, 1893
147 U.S. 1
The true line, in a navigable river between states of the union which separates the jurisdiction of one from the other, is the middle of the main channel of the river.
In such case, 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. The boundary line between the State of Iowa and the State of Illinois is the middle of the main navigable channel of the Mississippi River.
As the two states both desire that this boundary line be established at the places where the several bridges mentioned in the pleadings cross the Mississippi River, it is ordered that a commission be appointed to ascertain and designate at said places the boundary line between the two states, and that such commission 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.
The case is stated in the opinion. chanroblesvirtualawlibrary