David Hackett Souter

“ Although Kentucky has styled its acquiescence claim an affirmative defense, this "defense," if successfully proved, would not only counter Illinois' boundary claim but also establish Kentucky's own position. To do this on a theory of prescription and acquiescence, Kentucky would need to show by a preponderance of the evidence, first, a long and continuous possession of, and assertion of sovereignty over, the territory delimited by the transient low-water mark. Longstanding " [p] ossession and dominion are essential elements of a claim of sovereignty by prescription and acquiescence." ”

“ The territory in question, rather, is thought to be a comparatively narrow sliver of the Ohio along its northerly shore, where barges and watercraft would rarely venture. As to the sliver, Kentucky's acts of taxation have been, at best, equivocal, and the Special Master was accordingly correct when he observed that the fact of Kentucky's taxation of barges "traveling on the Ohio River within the acknowledged jurisdiction of Kentucky, does not support Kentucky's claim of exclusive jurisdiction of the entire breadth of the river." ”

“ Vessels traveling the river usually follow a sailing line charted by the United States Army Corps of Engineers which, for most of the stretch in question, is either close to the center of the river or near the Kentucky shore. Illinois does not dispute that the sailing line, like most of the river, is within the boundary and jurisdiction of Kentucky. ”