Hopper was born into a Quaker family in
Deptford Township, New Jersey in 1771. He married Sarah Tatum Hopper in 1795 and together they had ten children, including notable abolitionist
Abigail Hopper Gibbons, and a notable grandson
DeWolf Hopper. He became a Hicksite Quaker and a follower of
Elias Hicks. On June 26, 1827, he and his family transferred their membership to the Darby Friends Meeting. Following the
American Revolutionary War,
Pennsylvania abolished slavery before the end of the 18th century. The state, and especially the major port city of
Philadelphia, became a destination and byway for fugitive slaves escaping the South. In the years before the
American Civil War, Philadelphia was frequented by slave kidnappers, who often would capture free black children to sell into
slavery, as well as hunt fugitive slaves to return to their owners for reward. In the end, Hopper saved around 3,300 slaves. Hopper became an active and leading member of the
Pennsylvania Abolition Society, whose members frequently worked to protect the rights of African Americans, as well as to seek the end of slavery in the United States. In time, Hopper became known in Philadelphia as a friend and adviser to blacks in all emergencies. Hopper was an overseer of the Negro School for Children in Philadelphia, which was founded by the early abolitionist
Anthony Benezet before the Revolutionary War and operated through the nineteenth century. Hopper also served as a volunteer teacher in a free school for African-American adults. and lithographer
Henry R. Robinson, lampooning Hopper along with
Barney Corse and
David Ruggles as they face off with John P. Darg He was one of the founders and the secretary of a society for the employment of the poor; a volunteer prison inspector; a member of a fire company, and a guardian of abused
apprentices. Married and with a large family, he and his wife often extended their limited resources to take in more impoverished Quakers. Their children learned early to care for others. He also transacted much business for the
Society of Friends. In 1829, Hopper moved his family to New York to run a bookstore established by the Hicksite Quakers. In the autumn of 1830, being called to Ireland on business connected with his wife's estate, he visited England. In both countries, he was at first treated somewhat cavalierly by the orthodox Quakers, and was pointed out as the one "who has given Friends so much trouble in America." His amiable personality changed their unfavorable impressions. By the spring of 1841, the demand for Hicksite books had greatly diminished. Hopper became the treasurer and book agent for the
American Anti-Slavery Society in New York. ==Prison reform advocacy==