Born in Ithaca, New York, he attended the common schools and moved to Galena, Illinois in 1836, to Fort Snelling, Iowa, in 1838, and to Burlington in 1843, where he engaged in mercantile pursuits. He was mayor of Burlington in 1863 and a member of the Iowa House of Representatives from 1871 to 1873, serving as speaker for two terms.
Gear was Governor of Iowa from 1878 to 1881 and was elected as a Republican to the Fiftieth and Fifty-first Congresses, serving from March 4 1887 to March 3 1891. He was an unsuccessful candidate for reelection in 1890, but was appointed by President Benjamin Harrison as Assistant Secretary of the Treasury, serving from 1892 to 1893. He was elected to the Fifty-third Congress, serving from March 4 1893 - March 3 1895 and, in 1894, was elected to the United States Senate. Gear was reelected in 1900 and served from March 4 1895, until his death on July 14 1900, before the start of his second term. He had been chairman of the Committee on Pacific Railroads (Fifty-fourth through Fifty-Sixth Congresses).