Fugitive Slave Law
From Citizendium, the Citizens' Compendium
A series of U.S. laws dealing with the capture and return of runaway slaves. These laws were legitimated by Article IV of the U.S. Constitution.
The most egregious of these laws was the Fugitive Slave Act of 1850 which required, under penalties, the assistance and complicity of local law enforcement in the capture of runaway slaves.