Wabash, St. L. & P. Ry. Co. v. Illinois

Wabash Railway charged different rates to two shippers transporting goods over the same interstate route from Illinois to New York. Illinois convicted Wabash of unjust rate discrimination under a state statute; the Illinois Supreme Court upheld the statute, reasoning states could regulate matters Congress had not yet addressed.

Whether, under the Commerce Clause, states may regulate subjects that require a uniform national standard.