Why does this group of enslaved people in Massachusetts say that they should be free?

Chattel slavery developed in Massachusetts in the first decades of colonial settlement, and it thrived well into the 18th century. Various forms of slavery in New England predated the establishment of the Plymouth Colony in 1620 and the Massachusetts Bay Colony in 1630, but once established, colonists in both jurisdictions captured, purchased, and traded enslaved people—both African and Indigenous—on scale not previously seen in the region.[1] Although slavery in the United States is typically associated with the Caribbean and the Antebellum American South, enslaved people were prevalent throughout New England’s colonial history, and the practice was deeply embedded in the economic and social fabric of the region.[2]

The practice of slavery in Massachusetts was ended gradually, through case law. As an institution, it died out in the late 18th century through judicial actions litigated on behalf of slaves seeking manumission. Following England's lead, Lawyer Benjamin Kent represented slaves in court against their masters as early as 1752. He won the first case to liberate a slave in the United States in 1766. [3][4][5][6][7] The post-revolutionary court cases, starting in 1781, heard arguments contending that slavery was a violation of Christian principles and also a violation of the constitution of the commonwealth. 1783 saw additional high-profile court cases that began a general trend of slaves winning their emancipation on a case-by-case basis through lawsuit. As slavery dwindled in the last decade of the 18th century in Massachusetts, many of the instances where it remained, the slaveholders sometimes applied semantics of a name change to indentured servitude to maintain their property. The 1790 federal census, however, listed no slaves. Massachusetts was a center for the abolition movement in the 19th century. Legislation was passed that abolished slavery with the Thirteenth Amendment in 1865 was ratified by the stateExplanation:

i really do want to but i just don't know it i'm so sorry : (