Sargeant was also a farmer and served as Vice President of the Vermont Agricultural Society.

[3] He served in the War of 1812 as a member of the Vermont Militia company commanded by Abel Richardson.

[4] During the war, Sargeant made use of medical training obtained from his father to nurse sick and wounded soldiers.

[6] He was active in the Whig party, and served in numerous offices including probate judge, state's attorney, postmaster and justice of the peace.

[8][9][10][11] His legal career included the noteworthy defense of Stephen and Jesse Boorn, brothers who were convicted and sentenced to life in prison (Jesse) and death (Stephen) for the killing of Russell Colvin, a man missing from Manchester.