 The state of Iowa claimed that the rapids in question were the "rapids of the Des Moines River," which in fact were actually rapids in the Mississippi River and the starting point of the Sullivan Line.Justice Catron reviewed at length the facts which created the boundary dispute.Although he admitted that the Sullivan Line was "not a precisely true" line nor specific to the description contained in the Fort Clark and Portage des Sioux treaties, Justice Sullivan proposed investigating to what degree the federal government had respected the Sullivan Line.