While Rev. Freeman lived in Brooklyn in the mid-1850s, he secretly sheltered and aided Anna Maria Weems, a young fugitive slave, on her journey to freedom in Canada. Jacob Bigelow, a Washington, DC lawyer, disguised her as a boy. They met Dr. Ellwood Harvey of Philadelphia in front of the White House in November 1855, and Weems pretended to be a male buggy driver. She drove Harvey from Washington to Philadelphia, where Harvey took her to the house of another abolitionist, William Still, for Thanksgiving. The next day Dr. Harvey took Weems across the river to Camden, New Jersey, and on to New York City. In Brooklyn he took her to Rev. Charles Ray's house. Ray took her to the home of Lewis Tappan, where the only photo of Weems was taken in her "boy disguise". Rev. Freeman accompanied Weems from there by train to Canada, where she reached safety at her uncle and aunt's house in Ontario. It is likely that is where Freeman first met the radical American abolitionist, John Brown. Later Brown stopped at Freeman's church in Brooklyn in 1859, while en route to his raid at Harpers Ferry.