She strongly denied slavery

In a 1774 letter to her husband, she expressed her honest hope that there were no slaves in the province. Even though Abigail's father had been a slaver, she had always been adamantly opposed to the practice. Abigail said in March 1776, "I have often been ready to assume that the passion for liberty cannot be equally strong in the breasts of those who have been accustomed to deprive their fellow Creatures of theirs," in an attack on the blatant hypocrisy of slave-owning American rebels.

Adams thought that slavery was wrong and a danger to the experiment in American democracy. She questioned whether most Virginians had the "desire for Liberty" they claimed to have because they "deprive[d] their fellow Creatures" of freedom, according to a letter she wrote on March 31, 1776.

A significant occurrence in this regard occurred in Philadelphia in 1791 when a free black youngster asked her to teach him how to write. She then enrolled the youngster in a neighborhood evening school, despite opposition from a neighbor. Adams replied by saying he was "Is he to be denied training simply because he has a Black face, even though he is a Freeman just like the other young men? How will he be able to obtain employment? I didn't feel any embarrassment in taking him into my parlor to teach him how to read and write." The neighbor abruptly withdrew, and no additional concerns were voiced.