In his early life, Lincoln worked on the family farm, and attended the local school. He followed his father into public life, becoming town constable at 21, and in 1755 he joined the 3rd Regiment of the Suffolk County militia (where his father was colonel) as an adjutant. In 1756, at the age of 23, Lincoln married Mary Cushing, daughter of Elijah Cushing of Pembroke, Massachusetts, whose ancestors were also among the founders of Hingham. They had eleven children, seven of which survived to adulthood. In 1757, he was elected the town clerk of Hingham, a post he held for twenty years. He continued to be active in the militia during the French and Indian War, but saw no action, and was promoted to major by the end of the conflict in 1763.