Enslaved Person vs. Slave
Today, most historians refer to “enslaved people” instead of “slaves.” This language choice separates a person's identity from his/her circumstance. Likewise, saying “owner” or “master” empowers enslavers and dehumanizes enslaved persons, reducing them to commodities rather than someone who had slavery imposed on them. Using “enslaved” instead of “slave” and “enslaver” instead of “master” are subtle but powerful ways of affirming that slavery was forced upon someone, rather than an inherent condition. - Telling the Story: Enslavement of African People in the United States.
For more affirming language to use when writing about slavery, check out Writing About Slavery? This Might Help