There he became an influential mentor of Thomas Jefferson, who went on to be a leading proponent of the American Revolution, principal author of the Declaration of Independence, and the third President of the United States.
He attended Dundee Grammar School, and then Marischal College at the University of Aberdeen, where he received an MA in 1755.
In 1758, he was appointed Professor of Natural Philosophy at the College of William and Mary in Williamsburg, Virginia, then one of Britain's American colonies.
Recalling his years as a student, Jefferson described Small as: a man profound in most of the useful branches of science, with a happy talent of communication, correct and gentlemanly manners, and a large and liberal mind... from his conversation I got my first views of the expansion of science and of the system of things in which we are placed.In 1764, Small returned to Britain with a letter of introduction to Matthew Boulton from Benjamin Franklin.
Through this connection with Franklin, Small helped form the Lunar Society, a club of scientists and industrialists.