Henson was orphaned as a boy and was mistreated by his uncle. He ran away and lived on the streets for a while, until he was taken in by a Miss Janey, who ran a café where he worked and where he slept on the floor. He wanted to go to sea and a few years later walked to Baltimore, where he signed on as a cabin boy. His captain taught him until he died in 1882.
Then after a series of dead-end jobs he took a job in a hat shop, where he met Admiral Perry, a customer. Perry hired him as his assistant and they stayed together for 23 years. Henson saved the lives of Perry's expedition to Greenland in 1888 and learned fluent Inuit. On a later expedition he saved Perry's life again, and in 1909 Henson was the first non-Inuit to reach the north pole, 45 minutes before Perry, but because he was Black his primacy has been ignored. He also fathered several African-Inuit children, and there are still Inuit who acknowledge him as their ancestor.