Massachusetts Personal Liberty Act
The Massachusetts Personal Liberty Act, or "An Act to Protect the Rights and Liberties of the People of the Commonwealth of Massachusetts", was a Massachusetts law passed in response to the Federal Fugitive Slave Act passed as part of the Compromise of 1850. It aimed to stimey enforcement of that law within Massachusetts, and succeeded in that no fugitive slave was ever after captured within Massachusetts.
While the United States Constitution called on all states to return fugitive slaves to their masters, this provision had proven largely inconsequential in the North. It was expensive for slaveholders to travel there, and all too frequently they faced a hostile local judge. Slaveholders therefore began to protest as an increasing fraction of their "property" vanished north by the Underground Railroad.
In response, Congress passed the Fugitive Slave Act as part of the Compromise of 1850, which transferred all fugitive slave cases to new federal commissioners. Those commissioners would be hired specifically for the task, be paid based on the number of cases they handled, and be paid higher for returning a slave than for setting him free. Moreover, slaveholders (or their hired agents) could draft Northerners into a posse comutatis to aid them in recovering runaway slaves. This backfired on Northern sentiments: now they themselves were being called on to actively support slavery rather than simply to ignore it, and the commissioners were an unprecidented extension of federal power!
Matters came to a heat in the summer of 1854, when Charles Suttle of Alexandria, Virginia, appeared in Boston with Federal marshals to apprehend Anthony Burns, an escaped slave. Mobs followed them around the streets, screaming, "Here come the slave-catchers!" Despite this alarm, they managed to catch Burns and imprison him. A biracial crowd of two thousand, led by abolitionists, gathered outside the courthouse where he was being held and tried to forceably free him. Nonetheless, at a cost of $40,000, the federal government managed to send him down to Virginia.
The next year, the Massachusetts legislature passed "An Act to Protect the Rights and Liberties of the People of the Commonwealth of Massachusetts" to prevent the Fugitive Slave Act from being enforced in Massachusetts. It provided that any judge could issue the writ of habeas corpus, which would bring the fugitive slave's case into a state court to determine whether he was being rightfully detained. In that court, the burden of proof would be on the master to prove every fact "by the testimony of at least two credible witnesses, or other legal evidence equivalent thereto," and neither the slave's own statements nor the master's could be used in evidence.
Moreover, if anyone deported a slave without proving these matters to a state court, he could be fined up to $5,000 and imprisoned up to five years.
Finally, the Personal Liberty Act made being a Federal commissioner into an impeachable offense, and disbarred anyone who acted as attorney for someone trying to recapture a fugitive slave. It made it illegal for any state officer (including the militia) to help recapture a fugitive slave, and prohibited them from being held in state prisons. (As there were no federal prisons then, this one provision alone effectively prevented them from being imprisoned in Massachusetts.)
No fugitive slave was ever again returned from Massachusetts.
In the case Ableman v. Booth, the United States Supreme Court declared a similar Wisconsin law unconstitutional. However, this decision was rarely enforced; the South was still protesting in 1860 that the North was not returning fugitive slaves. The Crittenden Compromise, offered unsuccessfully two days before South Carolina seceded, would have again declared these Personal Liberty Acts unconstitutional and called on Northern states to repeal them.