On January 6, 1773, Massachusetts slaves petitioned the legislature for freedom. From the article:
"The Struggle for Freedom
There were several ways that a slave in colonial Massachusetts could gain his or her freedom. Perhaps the most straightforward, and by far the most dangerous, method was simply to run away. Individual documents about fugitive slaves are rare; newspaper advertisements for runaway slaves remain our best source. However documents such as a deposition about the runaway slave Pompey and a letter concerning a slave who was a stowaway on the ship Susan clearly demonstrate that some slaves chose this desperate course of action.
Another path to freedom was that of manumission (the legal act of freeing a slave), a tradition as old as the Roman Empire. Writs of manumission such as the statement on the second page of a receipt granting freedom to Cato were all that was required to free a slave; however, for a short time after the passage of a 1703 colonial law, no slave could be manumitted without posting a £50 bond with the municipal government (Greene, 1942; 138). This bond was intended to ensure that the former slave could be provided with food and lodging, in case of unemployment or illness. While this particular law remained in effect for about a year, the maintenance and care of elderly, infirm, and incapacitated former slaves remained a primary concern (principally for economic rather than humanitarian reasons) for colonial citizens. Slaves could also be manumitted by purchasing their own freedom. And while the exact process of purchasing freedom was seemingly not standardized, it was certainly possible as evidenced on the second page of a receipt for the sale of Corydon who paid £75 for his freedom.
Another option slaves had to gain their own freedom was that of legal petition. In the early 1770s, groups of Massachusetts slaves and freemen petitioned the colonial government, Detail of Petition to Thomas Gageclaiming that freedom was a right belonging to all men and women. Examples of petitions include one from June 1773, another from 25 May 1774, a third dated June 1774, and a fourth example dated January 1777. Even though there was much public discussion of liberty and freedom in the years leading up to the Revolution, the Massachusetts colonial government had little authority to end, or even curtail, slavery or the slave trade because of instructions from Parliament to the royal governor, and none of the petitions succeeded.
Individual slaves also could sue for their own freedom, either on the basis of a contractual agreement with the slave owner or, much later, on the basis of a natural right to freedom. While the former method was successful for individuals as early as 1701--in the case of Adam (see the manuscript agreement between John Saffin and Adam and The Selling of Joseph by Samuel Sewall), the latter argument would eventually bring about a legal end to slavery in Massachusetts. It is interesting to note that although slaves were clearly considered property under colonial law, and there were many laws restricting the activities of slaves (curfews, anti-fornication laws, etc.) there were also some circumstances where slaves were treated as citizens by the legal system. When charged with a crime, they had many of the same rights as free white citizens (trial by jury for example, although it would invariably be an all-white jury), and a contract made with a slave was just as binding as one made with a free man. John Adams remarked that he "never knew a Jury, by a Verdict to determine a Negro to be a slave -- They always found them free." While Adams often exaggerated to make a point, given this consistent pattern of juries finding in favor of slaves when they sued for their own freedom, it is not surprising that slavery was eventually abolished in Massachusetts by the judicial system rather than the legislature. (For more information, please see the next section of this website, "The Legal End of Slavery in Massachusetts.")."