Occurring under the presidency of John Tyler, "Prigg v. Pennsylvania" weakened the enforcement mechanisms of the Fugitive Slave Act of 1793 by allowing states to forbid their officials from cooperating in the return of fugitive slaves. But, by asserting federal government authority and responsibility over the area of fugitive slave return, it set the stage for future more stringent laws that would bypass individual state decisions about slavery. (Northern states by this time had abolished slavery, and most prohibited slaveowners from bringing slaves to their states, saying they would be considered free if brought in state.) Later, the Fugitive Slave Law of 1850 (part of the Compromise of 1850), required even free states to support capture and return of fugitive slaves with their law enforcement, increasing penalties for non-compliance.