Ward et al. v. Chamberlain et al. was a case heard by the United States Supreme Court in 1862 that dealt with the issue of slavery and its impact on interstate commerce. The plaintiffs, Ward and others, were African Americans who had been enslaved in Virginia but taken to Ohio for sale as slaves without their consent or knowledge. They argued that this violated both state laws prohibiting slavery and the federal Fugitive Slave Act of 1850 which prohibited transporting slaves across state lines without their consent or knowledge for any purpose other than returning them to their owners from whom they had escaped. The defendants, Chamberlain and others, argued that since no money changed hands during the transaction it did not constitute interstate commerce subject to regulation by Congress under Article I Section 8 of the Constitution which gives Congress power over "commerce among several states." In an opinion written by Chief Justice Taney, the court held that although there may have been some technical violations of law involved in taking these individuals out-of-state against their will for purposes related to slavery such acts do not constitute “commerce” within meaning of Article I Section 8 because they are not voluntary transactions involving goods or services exchanged between two parties; thus Congress has no authority over them under this clause even though they involve crossing state lines..

In Ward et al. v Chamberlain et al., the Supreme Court was asked to decide whether a state court had jurisdiction over an action brought by citizens of one state against citizens of another in which the amount in controversy exceeded $500. The majority opinion held that it did not, but Justice Grier dissented on the grounds that such a decision would be contrary to both common law and constitutional principles. He argued that states have concurrent jurisdiction with federal courts when it comes to cases involving diversity of citizenship, and thus should be allowed to hear cases where there is no federal question involved or where Congress has not provided for exclusive jurisdiction in the federal courts. Furthermore, he argued that allowing states to exercise their own authority over these matters would promote justice and prevent forum shopping among litigants who are seeking favorable outcomes from different jurisdictions.