Plumer was born in Newburyport, Province of Massachusetts Bay on June 25, 1759, the son of farmer and merchant Samuel Plumer and Mary Plumer. His family moved to Epping, New Hampshire in 1768, and he was raised at his father's farm on Epping's Red Oak Hill. Plumer attended the Red Oak Hill School until he was 17. Frequent ill health left him unsuited for military service during the American Revolution or life as a farmer, and after a religious conversion experience in his late teens, Plumer was trained as a Baptist exhorter. For several years he traveled throughout the state to deliver sermons to Baptist churches and revival meetings. He briefly considered a career as a doctor, and began to study medicine. Later deciding on a legal career, he studied law with attorneys Joshua Atherton of Amherst and John Prentice of Londonderry. While studying under Atherton, his fellow law clerks included William Coleman, who remained a lifelong friend. Plumer attained admission to the bar in 1787, and began to practice in Epping.
Early career
In addition to practicing law, Plumer was active in local politics and government. He held several town offices, including selectman. Plumer served in the New Hampshire House of Representatives from 1785 to 1786, in 1788, from 1790 to 1791, and from 1797 to 1800. In 1791 and 1797 he served as Speaker of the House. Plumer was a delegate to the state constitutional convention of 1791-1792.
U.S. Senate
Plumer was elected to the United States Senate as a Federalist, filling the vacancy caused when James Sheafe resigned. He served from June 17, 1802 to March 3, 1807, and was not a candidate for reelection. In 1803, Plumer was one of several New England Federalists who proposed secession from the United States due to lack of support for Federalists, rising influence of Jeffersonian Democrats and the diminished influence of the North due to the Louisiana Purchase. Recalling his involvement in the secession scheme in 1827, Plumer said, "This was, I think, the greatest political error of my life: & would, had it been reduced to practise , instead of releiving , destroyed New England....Fortunately for my own reputation the erroneous opinion I formed produced no bitter fruits to myself or my country."
Plumer served in the New Hampshire Senate in 1810 and 1811, and was chosen in both years to serve as the Senate's president.
Governor
By now a Democratic-Republican, in 1812, Plumer was the party's successful nominee for Governor of New Hampshire, and he served until 1813. He returned to office in 1816, and served until 1819.
In the 1820 presidential election, Plumer was one of New Hampshire's electoral college members. He cast the only dissenting vote in the Electoral College against incumbent President James Monroe, voting instead for John Quincy Adams. While some accounts say that this was to ensure that George Washington remained the only American president unanimously chosen by the Electoral College, others assert that he was instead calling attention to his friend Adams as a potential future presidential candidate, or protesting against the "wasteful extravagance" of the Monroe Administration. Plumer also eschewed voting for Daniel D. Tompkins for Vice President as "grossly intemperate" and having "not that weight of character which his office requires," and also "because he grossly neglected his duty" in his "only" official role as president of the Senate by being "absent nearly three-fourths of the time." Plumer instead voted for Richard Rush.
Plumer died in Epping on December 22, 1850 and was buried at the Plumer Family Cemetery in Epping.
Family
In 1788, Plumer married Sarah "Sally" Fowler of Newmarket, New Hampshire. They were the parents of six children -- William, Sally, Samuel, George Washington, John Jay, and Quintus. William Plumer Jr. was an author and attorney who served in the United States House of Representatives from 1819 to 1825.
