However, Thompson attempted to bypass the emancipation law by moving to Virginia, a slave state, and forcing James and his brother, sister, and parents to accompany him.

As part of the deal, James Mars and his brother agreed to work as slaves in Norfolk until they turned 25.

[9][7] Mars became a leader in New England's freedmen community and in African American reform movements for temperance and enfranchisement.

During the 1830s, he worked in a dry goods store in Hartford, Connecticut, where he helped found the Talcott Street Church, in which he served as deacon alongside minister James W. C.

[2] Mars was a principal in the 1837 landmark case Jackson v. Bulloch, in which the Connecticut Supreme Court freed a fugitive enslaved woman, Nancy Jackson, after she had lived two years in Connecticut with her Georgia captor, James Bulloch.

Circa 1845, the family moved to Pittsfield, Massachusetts, where he lived for twenty years, purchased land, farmed, and continued to participate in Black reform and antislavery movements.

[7] Mars explained that he wrote his memoirs because "some told me that they did not know that slavery was ever allowed in Connecticut, and some affirm that it never did exist in the State.