William Duer (March 25, 1805 – August 25, 1879) was an American lawyer and politician. In addition to serving in local offices in both California and New York, he represented New York in the United States House of Representatives from 1847 to 1851. A native of New York City, Duer was a member of a family long prominent in New York politics and government. He graduated from Columbia College in 1824, studied law in New York City, and attained admission to the bar in 1828. After practicing in Oswego for two years, he returned to New York City, where he continued practicing law. After a brief residence in New Orleans, in 1835 he returned to Oswego, where he became active in politics and government as a Whig. He served in the New York State Assembly for two one-year terms (1840 and 1841) and was Oswego County's District Attorney from 1845 to 1847. In 1846, Duer was elected to the U.S. House. He was reelected in 1848 and served two terms, 1847 to 1851. After leaving Congress, Duer served as U.S. Consul in Valparaíso, Chile for two years, then moved to San Francisco, where he practiced law and served as county clerk. In 1859 he returned to Oswego, where he was active in efforts to prevent the onset of the American Civil War. Once the conflict began, Duer supported the Union, but opposed the Republican Party and continued to advocate for concessions on the slavery and secession issues a way to end the war. In retirement, Duer resided on Staten Island. He died there in 1879 and was buried at Silver Mount Cemetery. Early life William Duer was born in New York City on March 25, 1805, the son of John Duer (1782–1858) and Anna Bedford Bunner Duer (1783–1864). William Duer was the grandson of Continental Congressman William Duer (1747–1799) and great-grandson of General William Alexander. Rudolph Bunner was his uncle. He graduated from Columbia College in 1824 and was the valedictorian of his class. He studied law, was admitted to the bar, and began to practice in Oswego. Start of career In 1830, Duer moved to New York City. Later that year, Duer and Elijah Paine Jr. published a reference work in octavo format, Practice of the Courts of Common Law in the State of New York. In 1832, he ran unsuccessfully for the New York State Assembly. He lived