He was born in York, Maine, in 1753, the son of a minister. As a young man he went to work as a clerk in a Kennebunk store owned by Waldo Emerson (not writer). He went into business with his boss and married his daughter, Sarah, in 1776. She was 14. He was said to have planted elm trees in front of the store on the day he heard about the Battles of Concord and Lexington.

Sarah had four children and died at 21 in 1784. Lyman inherited his father-in-law’s property and went into shipbuilding and merchant shipping, a rare Mainer who owned his own ships.