Solomon Northup is a thirty-three-year-old Black man living in Saratoga, New York, in 1841. He is happily married and has three children who he adores. He works as a carpenter and is also a skilled violinist who often plays for his friends. Solomon’s father was born into slavery but was freed by the lawyer Henry Northup, who remains a close friend of Solomon’s family. One day, two white men invite Solomon to temporarily perform as a violinist in their traveling circus, and Solomon enthusiastically agrees. Believing that he will only be gone for a few days, Solomon doesn’t tell his wife that he’s leaving. One night while in Washington, D.C., Solomon becomes sick and loses consciousness. When Solomon wakes up, he finds himself shackled in a dark cell.
Solomon discovers that he has been kidnapped by a slave trader named James Burch, who beats Solomon every time he insists that he’s a free man. The slave dealer sends Solomon and other kidnapped men, women, and children to New Orleans by ship. Once there, Solomon is told that his name is now “Platt.” A plantation owner named William Ford soon buys Solomon. Solomon describes Ford as a kind-hearted man who only condones slavery because he was raised with the belief that it is not immoral. Unfortunately, Ford runs into financial trouble and is forced to sell Solomon to a cruel carpenter named Tibeats. Tibeats has a short temper and tries to kill Solomon several times, but his efforts are thwarted by Ford and by Solomon himself.
Tibeats eventually sells Solomon to the brutal Edward Epps. Often drunk, Epps alternates between whipping his slaves and using them for entertainment. Epps regularly rapes a spirited, beautiful slave named Patsey, and as a result, Mrs. Epps despises her and takes pleasure in seeing her suffer. Both Epps and his wife treat Patsey with horrific brutality. Solomon constantly thinks about how to regain his freedom. He knows that he will be killed or captured if he tries to escape, so he feels that his best option would be to send a letter to his friends in Saratoga to obtain proof that he is a free man. However, all of his attempts to send a letter fail, and he often feels hopeless. His only solace is playing his violin, which allows him to earn money and enables him to occasionally leave the plantation to play at nearby houses.
After toiling and enduring terrible abuse on Epps’s plantation for ten years, Solomon meets Bass, a white carpenter working on Epps’s property. Bass is an abolitionist known for his unconventional opinions, and he and Solomon become friendly. One day, Solomon hears Bass arguing with Epps about slavery. Bass claims that slavery is morally wrong and says that there is no inherent difference between Black and white people. Epps thinks this is ridiculous, but Solomon feels hopeful that Bass can help him. Solomon explains his history to Bass and asks for Bass’ help in mailing a letter to Saratoga. Bass agrees but warns that after twelve years, everyone Solomon knows there might be dead. Bass mails the letter in August, but by Christmas there is still no response. Bass tells Solomon he plans to travel to Saratoga in the spring and will try to get in touch with Solomon’s acquaintances.
Meanwhile, the letter has been received in Saratoga and makes its way to Solomon’s wife. She contacts Henry Northup, who agrees to help restore Solomon’s freedom. Northup gets permission from the governor and travels to New Orleans. However, because everyone there knows Solomon as Platt, no one can help Henry Northup find Solomon. After some searching, Northup understands that Bass sent the letter and contacts him to learn of Solomon’s location.
On January 3, Solomon and the other slaves are working in the field when they see two men coming down from a carriage. Solomon is elated when he recognizes Northup. Northup tells Epps that Solomon is a free man, and Northup and Solomon leave the plantation. Solomon returns home to Saratoga, where he joyfully reunites with his wife and children.