What law did Congress pass that required all

escaped slaves be returned to their master?

The Fugitive Slave Act of 1850

Passed on September 18, 1850 by Congress, The Fugitive Slave Act of 1850 was part of the Compromise of 1850. The act required that slaves be returned to their owners, even if they were in a free state. The act also made the federal government responsible for finding, returning, and trying escaped slaves