The framers of the Constitution well understood that each locality, having separate and distinct interests, required separate and distinct laws, domestic institutions, and police regulations adapted to its own wants and its own condition; and they acted on the presumption, also, that these laws and institutions would be as diversified and as dissimilar as the States would be numerous, and that no two would be precisely alike, because the interests of no two would be precisely the same.

Speech in Chicago, Illinois (9 July 1858)