U.S. Supreme Court
Rhode Island v. Massachusetts, 45 U.S. 4 How. 591 591 (1846)
Rhode Island v. Massachusetts
45 U.S. (4 How.) 591
The grant of Massachusetts, confirmed in 1620, included the territory "lying within the space of three English miles on the south part of Charles River, or of any or every part thereof."
In 1662, the grant of Connecticut called to be bounded on the north by the line of the Massachusetts plantations.
In 1663, the grant of Rhode Island called to be bounded on the north by the southerly line of Massachusetts.
Whether the measurement of the three miles shall be from the body of the river, or from the headwaters of the streams which fall into it, is not clear. The charter may be construed either way without doing violence to its language.