What did southerners wont congress to do about enslaved people who had fled to the north?

Southerners wanted Congress to pass laws that would require northern states to return enslaved people who had fled to the North. They sought the enforcement of a strong Fugitive Slave Law, which would mandate the return of escaped enslaved individuals to their owners. This demand was rooted in the belief that enslaved people were property, and their escape was a violation of southern property rights. The debate over this issue heightened tensions between the North and South leading up to the Civil War.