He was a noted theologian and a serial Dissenting minister of Presbyterian (1761–1764), Baptist (1765–1803), and then Unitarian (1804–1815) congregations. His sympathy for both the American (1775–1783) and French (1787–1799) revolutions led the Englishman to be associated with the United States and gained the prolific historian the reputation of a religious radical. He was born to Caleb Toulmin and Mary Skinner, daughter of Thomas Skinner. At age eight, on 11 November 1748, he was admitted to St. Paul's School in London. As he grew, so did his nonconformist views. Because he refused to conform to the Church of England, he next was educated under David Jennings at the dissenting academy in Wellclose Square, of the Coward Trust, located on The Highway in the East End of London. On graduating from Wellclose Square Dissenting Academy, now Reverend (Rev.) he became the Presbyterian minister of his first congregation at Colyton, a civil parish located within east Devonshire. Although the Colyton congregation was Presbyterian, he eventually became a convert to the opinions of the Baptists. His theological objections to infant baptism possibly extended to infant registration, as none of his children's births were registered. Their eldest son, Harry Toulmin, went on to became a Unitarian minister and then emigrated to America, where eventually he was forced to resign as President of Transylvania Seminary in Lexington, Kentucky "under disapproval of his Socinian (Unitarian) errors." He lived in Taunton and had charge of the Taunton Baptist congregation at Mary Street Unitarian Chapel, where he also taught school and published most of his sixty-plus works through which he expressed his anti-England sympathy with both the American Revolutionary War (1775–1783) and the French Revolution (1787–1799).