Otis began working in a cotton factory at the age of 8 where he gained knowledge of mechanical engineering.

In 1851, he took control of the Pacific Mills of Manchester, Connecticut, and later established the Otis Manufacturing Company.

In his last years, Otis was in ill health and would spend winters in the South.

He attempted to return to New England, but he died when he reached Tarpon Springs on March 14, 1894.

[3] At the end of the war, he was named a brevet brigadier general with a promotion date of March 13, 1865.