The true test is, whether the object be of a local character, and local use; or, whether it be of general benefit to the states. If it be purely local, congress cannot constitutionally appropriate money for the object. But, if the benefit be general, it matters not, whether in point of locality it be in one state, or several; whether it be of large, or of small extent.
Joseph Story (1858). “Commentaries on the Constitution of the United States: with a preliminary review of the constitutional history of the colonies and states, before the adoption of the Constitution”, p.162
