[1] He worked on a farm in Temple, New Hampshire, served an apprenticeship to a clothier in Groton, Massachusetts, and, after graduation at Harvard in 1825, taught an academy in Lexington, Massachusetts, in 1825/26.

In 1828, Sherwin became submaster of the English High School of Boston, of which he had charge from 1838 until his death.

He was an originator of the American Institute of Instruction in 1830, its president in 1853/4, a member of the American Academy of Arts and Sciences, was active in establishing the Massachusetts Institute of Technology, and was president of the Massachusetts Teachers' Association in 1845.

[1] His son, also named Thomas Sherwin, was lieutenant colonel of the 22nd Massachusetts Regiment during the American Civil War.

The elder Thomas Sherwin died from heart disease at his home in Dedham, Massachusetts on July 23, 1869.