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.he earlier Fugitive Slave Act of 1793 was a Federal law which was written with the intent to enforce Article 4, Section 2 of the United States Constitution, which required the return of runaway slaves.