[2]: 2  William Smith was a successful farmer who served in local offices including justice of the peace and was a member of New Hampshire's Provincial Congress in 1774.

At age 16, Smith enlisted for the American Revolution in the Continental Army company of Captain Stephen Parker of New Ipswich, New Hampshire.

[1][2]: 17  He participated in the Battle of Bennington and was grazed by a musket ball which left a permanent scar on his throat.

[1][2]: 17–20  In 1782, Smith began to study law with attorney Shearjashub Bourne of Barnstable, Massachusetts, while working as a tutor in the home of Joseph Otis.

[2]: 22  He completed his legal studies with attorney William Pynchon of Salem, Massachusetts, while serving as headmaster of a school for girls.

[2]: 33  In addition, Smith served terms as town agent and a member of Peterborough's board of selectmen.

[1] As a House member, Smith voted against the impeachment of Woodbury Langdon, a judge of the state superior court.

[1] He was confirmed by the United States Senate on February 20, 1801, and received his commission the same day.

[2]: 444  In addition, they raised the daughter of William Smith and several nieces and nephews, as well as orphans they took into their home.