Alexander Ramsey was elected from Pennsylvania as a Whig to the U.S. House of Representatives and served in the 28th and 29th congresses from March 4, 1843 to March 3, 1847. He served as the first Territorial Governor of Minnesota from June 1, 1849 to May 15, 1853 as a member of the Whig Party.

In 1855, he became the mayor of St. Paul, Minnesota. Ramsey was elected the second Governor of Minnesota after statehood and served from January 2, 1860 to July 10, 1863. Ramsey is credited with being the first Union governor to commit troops during the American Civil War. He happened to be in Washington, D.C. when fighting broke out. When he heard about the firing on Ft. Sumter he went straight to the White House and offered Minnesota’s services to Abraham Lincoln. He resigned the governorship to become a U.S. Senator, having been elected to that post in 1863 as a Republican. He was re-elected in 1869 and held the office until March 3, 1875, serving in the 38th, 39th, 40th, 41st, 42nd, and 43rd congresses.

Ramsey served as Secretary of War from 1879 to 1881, under President Rutherford B. Hayes.