James W. Grimes (October 20, 1816 - February 7, 1872), born in Deering, New Hampshire, was an American politician, serving as the Whig governor of and senator from Iowa.
Grimes graduated from Hampton Academy; attended Dartmouth College, Hanover, N.H.; studied law; moved west and commenced practice in the 'Black Hawk Purchase', Wisconsin Territory, afterward the site of Burlington, Iowa. He also engaged in agriculture. Grimes served as a member of the Iowa Territorial House of Representatives 1838-1839, 1843-1844. He served as Governor of Iowa 1854-1858;
Grimes was elected as a Republican to the United States Senate in 1859 and reelected in 1865 He served from March 4, 1859, until December 6, 1869, when he resigned due to ill health. He served as chairman of the Committee on the District of Columbia (37th and 38th Congresses), the Committee on Naval Affairs (39th through 41st Congresses). In 1861 Grimes was a member of the peace convention held in Washington, D.C., in an effort to devise means to prevent the impending Civil War. He voted against convicting Andrew Johnson after Johnson was impeached by the House of Representatives in 1868.
Grimes died in Burlington, Iowa, February 7, 1872.