His involvement in politics also increased, and he gradually rose through the ranks of the local, and then national government, being elected by the Connecticut legislature to the United States Senate.

[1][2] His father, son of the first minister of the Congregational Church,[3] was a "prosperous farmer", well educated and well versed in local politics – he was 21 times elected as a member of the General Assembly of Connecticut – and was familiar with "civil and military concerns of the town.

[1][2] Under Captain Isaac Bostwick, Boardman served in one of the first sixteen regiments raised by the Continental Congress under the command of Colonel Charles Webb.

Boardman was directed to Boston, and diverted to New London and New York City, where he took part in Battle of Long Island, however after defeat there and American evacuation to Washington, he was confined to a sick bed having exacerbated childhood medical difficulties and fever.

[1] After six months, having achieved an ultimate rank of sergeant,[4] he obtained passage on a wagon back to New York, where he was discovered in poor health by a friend of his father, who sent word home for Boardman to be collected.

He spent time employed in New Haven, training as a shopkeeper in the store of Elijah and Archibald Austin,[2] before setting up his own company in his home town of New Milford later that same year.

[5] In 1789, he was the subject of a portrait by Ralph Earl, which "portrayed the richly dressed dry goods merchant... in his store in New Milford... through the open door, bolts of textiles tell the viewer how Boardman earned a living.

His cause of death is a subject of speculation, however biographer and son-in-law John Frederick Schroeder (m. Caroline Maria Boardman) related it while writing in 1849 to several bouts of cholera and fever Boardman had suffered throughout his life, particularly during a tour of Rhode Island in 1780, as well as other attacks in Vermont and New Hampshire throughout his life.