Garnet was a prominent member of the movement that led beyond moral suasion toward more political action. Renowned for his skills as a public speaker, he urged black Americans to take action and claim their own destinies. For a period, he supported emigration of American free blacks to Mexico, Liberia, or the West Indies, but the American Civil War ended that effort. In 1841 he married abolitionist Julia Williams and they had a family. Stella (Mary Jane) Weems, a runaway slave from Maryland, lived with the Garnets. She may have been adopted by the Garnets or worked as a governess for them. When Henry would preach against slavery he would bring up Stella. Stella would talk about her own experiences and about her family still enslaved in Maryland. While on a trip preaching in England Garnet was hired by a Scottish church as a missionary. They moved to Jamaica in 1852. However, they were not there long when the family came down with yellow fever. Stella died and was buried there. Garnet and his family, though sickened, boarded a ship for America. After the war, the couple worked in Washington, DC.