Trumbull was the son of the Connecticut governor Jonathan Trumbull (a first cousin to the poet John Trumbull (Trumbull, John)). A boyhood injury to his left eye made him virtually monocular. After graduating from Harvard College in 1773, he worked as a teacher. During the American Revolution he served as an aide to General George Washington (Washington, George) and achieved the rank of colonel.

In 1780 Trumbull went to London via France, but, in reprisal for the hanging of the British agent Major John André by the Americans, he was imprisoned there. Once released, he returned home but subsequently went back to London by 1784 to study with the painter Benjamin West (West, Benjamin).

At the suggestion of West and with the encouragement of Thomas Jefferson (Jefferson, Thomas), Trumbull about 1784 began the celebrated series of historical paintings and engravings that he was to work on sporadically for the remainder of his life. From 1789 he was in the United States, but he returned to London in 1794 as secretary to John Jay (Jay, John). He remained there for 10 years as a commissioner for the implementation of the Jay Treaty. During this period, in 1800, he married Sarah Hope Harvey, an English amateur painter. Moving back and forth between England and the United States, in 1808 he attempted portrait painting in London but met with little success. From 1815 to 1837 he maintained a rather unsuccessful studio in New York City.

In 1817 Trumbull was commissioned by the U.S. Congress to paint four large pictures in the rotunda of the Capitol at Washington, D.C.: Washington Resigning His Commission, The Surrender of Cornwallis, The Surrender of Burgoyne, and, best known of all, Declaration of Independence. This series, which he completed in 1824, was based on the small and superior originals of these scenes that he had painted in the 1780s and '90s. In 1831 Benjamin Silliman (Silliman, Benjamin), a professor at Yale, established the Trumbull Gallery at Yale, the first art gallery at an educational institution in America. Trumbull gave his best works to this gallery in exchange for an annuity.

American poet and jurist, known for his political satire, and a leader of the Hartford wits (q.v.).

While a student at Yale College (now Yale University), Trumbull wrote two kinds of poetry: “correct” but undistinguished elegies of the Neoclassical school, and brilliant, comic verse that he circulated among friends. His burlesque “Epithalamium” (1769) combined wit and scholarship, and his essays in the style of Joseph Addison were published in The Boston Chronicle in 1770. While a tutor at Yale he wrote The Progress of Dulness (1772–73), an attack on educational methods.

He passed the bar examinations in 1773 and moved to Boston. His major work was the comic epic M'Fingal (1776–82). Despite its pro-Whig bias, its reputation as anti-Tory propaganda has been exaggerated.

His literary importance declined after 1782, as he became increasingly interested in law and politics. He first held office in 1789 as a state's attorney and subsequently as a state legislator and a judge until 1819.