Massachusetts abolished slavery in 1783, when the state’s Supreme Judicial Court ruled in Commonwealth v. Jennison that the practice could not survive under the 1780 Massachusetts Constitution. No single statute ended it. Instead, the constitution’s Declaration of Rights supplied the principle, and a series of court decisions between 1781 and 1783 gave that principle legal force. By the 1790 federal census, Massachusetts was the only state in the new nation to report zero enslaved people.1Mass.gov. Massachusetts Constitution and the Abolition of Slavery
The 1780 Constitution Set the Principle
The constitutional convention that drafted the state’s new governing document, with John Adams as principal author, produced a Declaration of Rights whose Article I reads: “All men are born free and equal, and have certain natural, essential, and unalienable rights; among which may be reckoned the right of enjoying and defending their lives and liberties; that of acquiring, possessing, and protecting property; in fine, that of seeking and obtaining their safety and happiness.”2General Court of Massachusetts. Massachusetts Constitution
Voters ratified the document at town meetings, and it took effect in 1780. The text never used the word “slavery.” That silence left the practical question open: did “born free and equal” actually free the people then held in bondage? The courts answered it over the next three years.
The Court Cases That Ended Slavery
Brom and Bett v. Ashley (1781)
The first test came quickly. Elizabeth Freeman, known as “Mum Bett,” was enslaved by Colonel John Ashley of Sheffield. Her lawyer, Theodore Sedgwick, filed a writ of replevin, a legal action normally used to recover property, and argued that under the new constitution’s equality language Freeman and a man named Brom were not legitimately Ashley’s property.3National Constitution Center. Elizabeth Freeman, Her Case for Freedom, and the Massachusetts Constitution
The County Court of Common Pleas in Great Barrington agreed. The jury found that neither Freeman nor Brom belonged to Ashley and awarded them 30 shillings in damages plus court costs. Ashley did not appeal. The case established that the constitution’s language could be used to free an individual, but it did not yet settle the broader question for the whole state.
The Quock Walker Cases (1781–1783)
That broader question was settled through three related proceedings involving an enslaved man named Quock Walker. Walker had been held by Nathaniel Jennison, whose wife’s first husband had reportedly promised Walker his freedom by age 25. In 1781, Walker left Jennison’s household. Jennison tracked him down, beat him, and forced him back.1Mass.gov. Massachusetts Constitution and the Abolition of Slavery
Walker sued Jennison for assault and battery in the Worcester County Court of Common Pleas. The jury found Walker a free man and awarded him 50 pounds in damages. In a separate action, Jennison sued the men who had taken Walker in, claiming they had stolen his property, and won 25 pounds. Two juries in the same county had reached opposite conclusions.1Mass.gov. Massachusetts Constitution and the Abolition of Slavery
The decisive case, Commonwealth v. Jennison, reached the Supreme Judicial Court in April 1783. This time the state itself prosecuted Jennison for criminal assault. Chief Justice William Cushing instructed the jury that slavery had been “countenanced by the Province Laws formerly” but had never been “expressly enacted or established.” He described it as a practice that “took its origin from the practice of some of the European nations, and the regulations of British government respecting the then Colonies, for the benefit of trade and wealth.”4Library of Congress. The Abolition of Slavery in Massachusetts
Then came the line that effectively ended slavery in the state. Cushing told the jury that “slavery is in my judgment as effectively abolished as it can be by the granting of rights and privileges wholly incompatible and repugnant to its existence,” and that “perpetual servitude can no longer be tolerated in our government.” The jury convicted Jennison.1Mass.gov. Massachusetts Constitution and the Abolition of Slavery
The practical meaning was blunt. Any slaveholder who tried to physically control or confine a person they claimed to own could now face criminal prosecution for assault or unlawful imprisonment. The legal mechanism that had made slavery enforceable collapsed. Twenty-five years later, in Inhabitants of Winchendon v. Inhabitants of Hatfield (1808), the same court looked back on Walker and summarized it directly: “the judges declared, that, by virtue of the first article of the declaration of rights, slavery in this state was no more.”5National Constitution Center. Instructions to the Jury in the Quock Walker Case, Commonwealth of Massachusetts v. Nathaniel Jennison
What Changed in Practice
Legal rulings and real life do not always match, but in Massachusetts they converged within a few years. After Walker, slaveholders faced criminal liability for enforcing their claims. Some enslaved people walked away. Others received formal releases. Local officials began reclassifying people who had been listed as taxable property as free residents.
The 1790 federal census recorded the result. Massachusetts reported zero enslaved people, the only state in the nation to do so.1Mass.gov. Massachusetts Constitution and the Abolition of Slavery Vermont, which had banned slavery in its 1777 constitution, still recorded 16 enslaved people in the same census. The 1800 census again reported zero for Massachusetts.
Historians debate how much weight to give the court rulings against broader economic and cultural shifts. The Walker case was not widely reported at the time, and changing economic conditions along with growing public opposition to slavery played their own roles. But the legal path mattered. Massachusetts did not pass a gradual emancipation statute like Pennsylvania, Connecticut, or New York, where slavery persisted for decades under phase-out schedules. Constitutional language plus judicial enforcement ended it outright.
The Limits of State Abolition
Ending slavery inside Massachusetts did not shield the state from federal slave law. The federal Fugitive Slave Act of 1793, and its harsher successor in 1850, required all states to return people who had escaped slavery to those who claimed them, and enforcement actions continued to reach into Massachusetts. In 1854, Anthony Burns, who had escaped slavery in Virginia, was arrested in Boston under the Fugitive Slave Act and, after federal troops were ordered to the city, marched in shackles to a waiting ship. Massachusetts responded with the 1855 Personal Liberty Act, which barred state officials from assisting fugitive slave recovery and imposed criminal penalties on anyone who removed a person from the state under such a claim. The conflict between the state’s 1783 abolition and federal slave law was not resolved until the Thirteenth Amendment abolished slavery nationwide in 1865.