The most explosive element in the Compromise of 1850 was the Fugitive Slave Law, which required the return of runaway slaves. Any black--even free blacks--could be sent south solely on the affidavit of anyone claiming to be his or her owner. The law stripped runaway slaves of such basic legal rights as the right to a jury trial and the right to testify in one's own defense.
Under the Fugitive Slave Law, an accused runaway was to stand trial in front of a special commissioner, not a judge or a jury, and that the commissioner was to be paid $10 if a fugitive was returned to slavery but only $5 if the fugitive was freed. Many Northerners regarded this provision as a bribe to ensure that any black accused of being a runaway would be found guilty. Finally, the law required all U.S. citizens and U.S. marshals to assist in the capture of escapees. Anyone who refused to aid in the capture of a fugitive, interfered with the arrest of a slave, or tried to free a slave already in custody was subject to a heavy fine and imprisonment.
The Fugitive Slave Law produced widespread outrage in the North and convinced thousands of Northerners that slavery should be barred from the western territories.
Attempts to enforce the Fugitive Slave Law provoked wholesale opposition. Eight northern states enacted "personal liberty" laws that prohibited state officials from assisting in the return of runaways and extended the right of jury trial to fugitives. Southerners regarded these attempts to obstruct the return of runaways as a violation of the Constitution and federal law.
The free black communities of the North responded defiantly to the 1850 law. They provided fugitive slaves with sanctuary and established vigilance committees to protect blacks from hired kidnappers who were searching the North for runaways. Some 15,000 free blacks emigrated to Canada, Haiti, the British Caribbean, and Africa after the adoption of the 1850 federal law.
The South's demand for an effective fugitive slave law was a major source of sectional tension. In Christiana, Pennsylvania, in 1851, a gun battle broke out between abolitionists and slave catchers, and in Wisconsin, abolitionists freed a fugitive named Joshua Glover from a local jail. In Boston, federal marshals and 22 companies of state troops were needed to prevent a crowd from storming a court house to free a fugitive named Anthony Burns.
