High Quality Content by WIKIPEDIA articles! The Fugitive Slave Law or Fugitive Slave Act was passed by the United States Congress on September 18, 1850, as part of the Compromise of 1850 between Southern slave holding interests and Northern Free-Soilers. This was one of the most controversial acts of the 1850 compromise and heightened Northern fears of a 'slave power conspiracy'. It declared that all runaway slaves be brought back to their masters. Abolitionists nicknamed it the "Bloodhound Law" for the dogs that were used to track down runaway slaves.