When he was fifteen he went to a corn husking, where he noticed a group of slaves brought to the husking by a slave dealer named Stephen Holland. While the other whites in the party dined, the young Quaker remained behind to talk with the slaves and to "see if I could render them any service". He learned that one of the slaves, named Stephen, was freeborn and a former indentured servant to Edward Lloyd, a Philadelphia Quaker, but later had been kidnapped and sold into slavery. Coffin arranged with a "trusty negro, whom I knew well," to take Stephen the next night to his father's house. After learning the particulars of the now slave's case, the elder Coffin wrote to Edward Lloyd informing him of his former servant's plight and eventually Stephen was liberated from slavery in Georgia.
In 1821 with his cousin Vestal Coffin he opened a Sunday school for slaves. They used the Bible to teach them to rea, with considerable success. However there were influential people who actively discouraged slave owners from allowing their slaves to attend, and the school was forced to close.
In 1824 Levi married Catharine White, whom he had known since childhood and who shared his abhorrence of slavery. When repression in North Carolina became stronger and stronger, Coffin and his Quaker associates decided to move to Newport (Fountain City) in Indiana where African Americans could live in freedom. There he opened a country store which became very successful.
Coffin was dedicated to peaceful measures to bring about the abolition of slavery. His home became the centre for the Underground Railroad which took runaway slaves north to Canada and freedom. Escaping slaves could only travel safely in the hours of darkness and had only the North Star as a guide. During the day they often hid in the homes or on the property of anti-slavery supporters. These “stops” on the way to freedom became known as the Underground (secret) Railroad stations, as they resembled the stops that a train might make on a journey.
Coffin became known as the “president” of a loose federation of people who assisted fugitive slaves. It is estimated that Levi and his wife Catharine helped more than 2,000 slaves to freedom during the 20 years that they lived in Newport. One of the slaves who escaped was Eliza Harris, whose story is told in Harriet Beecher Stowe’s novel Uncle Tom’s Cabin. Catharine and Levi Coffin were depicted as Simeon and Rachel Halliday. The fearlessness the Coffins showed in offering assistance to the fleeing slaves had an effect on their neighbours. Levi Coffin noted that those who had once "stood aloof from the work" eventually contributed clothing for the fugitives and aided the Coffins in forwarding the slaves on their way to freedom, but were "timid about sheltering them under their roof; so that part of the work devolved on us."
“Free produce”, (goods produced by free labour), was advocated by Coffin and he travelled widely in the South promoting these goods. In 1847 he started a warehouse in Cincinnati, dealing in free produce to supply stores that wished to sell these goods. As he was a skilled businessman the warehouse prospered for a time but was not profitable so he was forced to close it in 1857. During this time he continued working with the Underground Railroad and helped another 1,300 slaves to freedom. He also continued with his work in education. During the Civil War many slaves gained their freedom and he contributed to the Freedmen’s Aid Associations that were established to help freed slaves. He went to England in 1864 and raised over $100,000 for his work and was instrumental in the formation of an Englishmen’s Freedmen’s Aid Society. In 1867 he attended the International Anti-Slavery Conference in Paris.
He died in 1877. His house is now a National Historic Landmark.