Arright, you got me interested enough to google it.

Adams did not own enslaved people. Instead, the Adamses hired white and free African-American workers to provide these services. However, that did not mean that they avoided slavery altogether. While the Adamses opposed slavery both morally and politically, they tolerated the practice in their daily lives and they may have hired out enslaved African Americans, paying wages to their owners, to work in the Vice President’s and President’s House. ... Abigail finally came to the conclusion that she would only hire American-born servants and that enslaved African Americans were the most reliable of that group: “the chief of the Servants here who are good for any thing are Negroes who are slaves, the white ones are all Foreigners & chiefly vagabonds.”

-Top google result of "john adams slaves"