William H. Seward
Seward served as a state senator of New York from 1831 to 1834, as Governor of New York from 1839 to 1843, and as a United States Senator from New York from 1849 through 1861. Abraham Lincoln appointed him Secretary of State in 1861 and he served until 1869.
As Secretary of State, he fought for the U.S. purchase of Alaska which he finally negotiated to acquire from Russia for $7,200,000 on March 30, 1867. This translated into approximately 2.5 cents per acre for 586,400 square miles of territory, three times the size of Texas. The purchase of this frontier land ("Seward's Icebox") was mocked as "Seward's Folly" and Andrew Johnson's "polar bear garden".