The Threat to Slavery

Abstract

Abstract This chapter examines a series of antebellum court cases concerning the mobility of black people and immigrants. In Commonwealth v. Aves (1836), the Massachusetts Supreme Court ruled that an enslaved person brought into a free state was automatically free. In Groves v. Slaughter (1841), the US Supreme Court examined congressional and local power over the interstate slave trade. In Prigg v. Pennsylvania (1842), the Court ruled that states could not infringe on the federal government’s power to return fugitive slaves, but neither did they have to enforce federal laws. Northern states passed new personal liberty laws in response, while southern states demanded a stronger fugitive slave act. In the Passenger Cases (1849), the Supreme Court invalidated two state immigration laws as violations of federal commerce power, but the four dissenters, led by Chief Justice Roger Taney, defended these laws as legitimate exercises of police power and warned that southern states risked losing control over black mobility.