[522] Federalist No. 32.

[523] 9 Wheat. 1, 11, 226 (1824).

[524] Madison, IV, Letters and Other Writings, 14-15 (Philadelphia, 1865).

[525] 9 Wheat. 1, 203.

[526] 9 Wheat. at 210-211.

[527] 9 Wheat. at 13-14; also ibid. 16.

[528] 9 Wheat. 17-18, 209.

[529] 12 Wheat. 419 (1827).

[530] 12 How. 299 (1851).

[531] Congressional regulation of commerce, however, does not have to be uniform. The uniformity rule is a test of the invalidity of State legislation affecting commerce, not the validity of Congressional legislation regulating commerce. Clark Distilling Co. v. W.M.R. Co., 242 U.S. 311, 327 (1917); Currin v. Wallace, 306 U.S. 1, 14 (1939); Prudential Ins. Co. v. Benjamin, 328 U.S. 408 (1946).