This case concerns the Green Bay section of the boundary between these States. In Michigan v. Wisconsin, 270 U.S. 295, 46 S.Ct. 290, 296, 70 L.Ed. 595, the entire boundary was involved. As to that section, the question was whether islands within the bay and other islands surrounded by its waters and those of Lake Michigan belonged to one or the other State. The territory of Wisconsin was created by an Act of April 20, 1836, c. 54, 5 Stat. 10. The stretch of boundary in question is described: '* * * to a point in the middle of said lake (Michigan), and opposite the main channel of Green Bay, and through said channel and Green Bay to the mouth of the Menominee river. * * *' Section 1. By the Enabling Act of June 15, 1836, c. 99, 5 Stat. 49, under which Michigan became a State January 26, 1837, it is described in the reverse direction: '* * * thence, down the centre of the main channel of the same (Menominee river), to the centre of the most usual ship channel of the Green bay of Lake Michigan; thence, through the centre of the most usual ship channel of the said bay to the middle of Lake Michigan. * * *' Section 2.
As to the section there involved, we said: 'In determining the boundary through this section, the question is not embarrassed by differences of description. (270 U.S. 295, page 314, 46 S.Ct. 290, 296, 70 L.Ed. 595) * * * The evidence shows that there are two distinct ship channels, to either of which this description might apply. From the mouth of the Menominee, the channel, according to the Michigan claim, proceeds across the waters of Green Bay in an easterly direction until near the westerly shore of the Door county peninsula; thence, in close proximity to the shore, in a northerly direction to a point opposite Death's Door channel (or Porte des Morts); thence through that channel into Lake Michigan. The channel claimed by Wisconsin, after leaving the mouth of the Menominee, turns to the north and pursues a northerly direction to a point opposite the Rock Island passage, which lies between Rock Island and St. Martin's Island; thence through the Rock Island passage into Lake Michigan. The territory in dispute lies between these rival channels, and embraces two groups of islands: (1) Chambers Island, the Strawberry Islands, and a few others, small and unnamed, all within the main waters of Green Bay west of the Door county peninsula; and (2) Rock, Washington, Detroit, and Plum Islands, lying between Death's Door channel and the Rock Island passage, at the north end of the peninsula. The evidence as to which of the two ship channels was the usual one at the time of the adoption of the Michigan Enabling Act is not only conflicting, but of such inconclusive character that, standing alone, we could base no decree upon it with any feeling of certainty. (270 U.S. 295, page 315, 46 S.Ct. 290, 297, 70 L.Ed. 595) * * * But it is not necessary, for * * * the title of Wisconsin to the disputed area now in question is established by long possession and acquiescence, and this conclusion is justified by evidence and concessions of the most substantial character. (270 U.S. 295, page 316, 46 S.Ct. 290, 297, 70 L.Ed. 595) * * * The result is that complainant has failed to maintain her case in any particular, and that the claims of Wisconsin as to the location of the boundary in each of the three sections are sustained.' 270 U.S. 295, page 319, 46 S.Ct. 290, 298, 70 L.Ed. 595.
The decree (272 U.S. 398, 47 S.Ct. 114, 71 L.Ed. 315) defines the section: 'thence down the center of the main channel of the * * * Menominee to the center of the harbor entrance of said Menominee river; thence in a direct line to the most usual ship channel of Green Bay, passing to the north of Green Island and westerly of Chambers Island and through the Rock Island Passage into Lake Michigan, by courses and distances as follows: From a point midway between the outer ends of the Menominee river piers; thence east by south, seven and one-half miles to the center of the most usual ship channel of the Green Bay; thence along said ship channel north by east one-eighth east, eight and seven-eighths miles; thence continuing along said ship channel north by east seven-eighths east, twenty-seven miles; thence continuing along said ship channel, east one-fourth north, ten and one-fourth miles; thence east three-fourths north to the boundary between the state of Michigan and the state of Wisconsin in the middle of Lake Michigan.'