As a child he was remarkably precocious; at six he is said to have been able to repeat large parts of the Bible and of Pilgrim's Progress by heart. He graduated as valedictorian of his class at Dartmouth College in 1819, was a tutor therein 1819-1820, spent a year in the law school of Harvard University, and studied for a like period at Washington, in the office of William Wirt, then attorney-general of the United States. He was admitted to the Massachusetts bar in 1823 and practised at what was later South Danvers (now Peabody) for five years, during which time he served in the Massachusetts House of Representatives (1825-1826) and in the state senate (1827).

In 1828 he removed to Salem, where his successful conduct of several important lawsuits brought him prominently into public notice. In 1830 he was elected to Congress as a Whig from the Salem district, defeating the Jacksonian candidate for re-election, BW Crowninshield (1772-1851), a former secretary of the navy, and in 1832 he was re-elected. His career in Congress was marked by a notable speech in defence of a protective tariff.

In 1834, before the completion of his second term, he resigned and established himself in the practice of law in Boston. Already his fame as a speaker had spread beyond New England, and he was much sought after as an orator for public occasions. For several years he devoted himself unremittingly to his profession, but in 1841 succeeded Daniel Webster in the United States Senate. Shortly afterwards he delivered one of his most eloquent addresses at the memorial services for President Harrison in Faneuil Hall, Boston.

In the Senate he made a series of brilliant speeches on the tariff, the Oregon boundary, in favor of the Fiscal Bank Act, and in opposition to the annexation of Texas. On Webster's re-election to the Senate, Choate resumed (1845) his law practice, which no amount of urging could ever persuade him to abandon for public office, save for a short term as attorney-general of Massachusetts in 1853-1854. In 1853 he was a member of the state constitutional convention. He was a faithful supporter of Webster's policy as declared in the latter's famous Seventh of March Speech (1850) and labored to secure for him the presidential nomination at the Whig national convention in 1852.

In 1856 he refused to follow most of his former Whig associates into the Republican Party and gave his support to James Buchanan, whom he considered the representative of a national instead of a sectional party. In July 1859 failing health led him to seek rest in a trip to Europe, but he died on the 13th of that month at Halifax, Nova Scotia, where he had been put ashore when it was seen that he probably could not outlive the voyage across the Atlantic.

Choate, besides being one of the ablest of American lawyers, was one of the most scholarly of American public men, and his numerous orations and addresses were remarkable for their pure style, their grace and elegance of form, and their wealth of classical allusion.

His Works (edited, with a memoir, by SG Brown) were published in 2 vols. at Boston in 1862. The Memoir was afterwards published separately (Boston, 1870). See also EG Parker's Reminiscences of Rufus Choate (New York, 1860); EP Whipple's Some Recollections of Rufus Choate (New York, 1879); and the Albany Law Review of 1877-1878).