The U.S. Supreme Court case of Indiana v. Kentucky in 1895 was a territorial dispute over the boundary line between the two states along the Ohio River. The controversy arose from differing interpretations of an agreement made by Virginia (which originally claimed both territories) in its 1784 cession to Congress, and subsequent state constitutions and acts admitting them into the Union as separate states. Indiana argued that it had jurisdiction up to low-water mark on northwestern side of river, while Kentucky claimed jurisdiction extended to high-water mark on same side based upon historical practice and acquiescence by Indiana for many years. The Supreme Court ruled in favor of Kentucky, stating that although original documents were ambiguous regarding exact boundaries, long-standing acceptance by both parties established de facto borders which should be respected under principles of stability and respect for sovereign rights within federal system. Thus, despite some ambiguity about original intent or language used when these areas became individual states, practical considerations led court to uphold existing border arrangements.

In the dissenting opinion for Indiana v. Kentucky, Justice Harlan argued that the majority's decision to uphold an 1820 compact between Indiana and Kentucky determining their shared border was incorrect. He contended that this agreement was not legally binding because it had never been ratified by Congress as required by Article I, Section 10 of the U.S. Constitution which states any agreement or compact between two or more states must have Congressional consent. Furthermore, he believed that even if such a ratification had occurred, it would still be invalid due to changes in circumstances since its creation - specifically citing shifts in river courses over time affecting boundary lines. Therefore, according to Justice Harlan's interpretation of constitutional law and geographical considerations, he disagreed with his colleagues' ruling on this case.