Brown v. Wiley is a United States Supreme Court case from 1866 that dealt with the issue of slavery. The case involved a dispute between two former slaves, Brown and Wiley, over the ownership of a piece of property. Brown had purchased the property from Wiley, but Wiley later claimed that he had not been legally emancipated and thus had no right to sell the property. The Supreme Court ruled in favor of Brown, finding that Wiley had been legally emancipated and thus had no right to reclaim the property. The Court also held that the sale of the property was valid and binding, and that Brown was the rightful owner. The decision in Brown v. Wiley was significant in that it established the principle that former slaves were legally emancipated and had the same rights as any other citizen. This ruling was a major step forward in the fight for civil rights for African Americans, as it established that they had the same rights as any other citizen. The decision also set a precedent for future cases involving the rights of former slaves.

In Brown v. Wiley, the Supreme Court was asked to decide whether a state could constitutionally tax a federal corporation for its property and income within the state's borders. The majority opinion held that such taxation was constitutional, but Justice Field dissented from this decision. He argued that Congress had exclusive authority over interstate commerce and thus any attempt by states to levy taxes on corporations engaged in it would be unconstitutional as an infringement of congressional power. Furthermore, he contended that if states were allowed to tax these corporations then they would have too much control over them which could lead to discrimination against out-of-state companies or favoritism towards in-state ones. Finally, he noted that allowing such taxation would also create confusion since different states might impose different rates or exemptions leading to unequal treatment of similar businesses across jurisdictions.