A graduate (1820) of Union College, he was admitted to the bar in 1822 and established himself as a lawyer in Auburn, N.Y., which he made his lifelong home. He was active in the Anti-Masonic party and later joined the Whig party. Seward and his close personal and political friend, Thurlow Weed, became the two most influential Whigs in New York state. A state senator from 1830 to 1834, he ran unsuccessfully for the governorship in 1834. In 1838, however, he won that office, and he was reelected in 1840. As governor, Seward worked for educational reforms and internal improvements; he also secured legislation to better the position of immigrants and to protect fugitive slaves. He returned to his law practice in 1843.
Seward was elected to the U.S. Senate in 1849. Reelected in 1855, he was one of the Senate's most prominent members in the troubled years preceding the Civil War. A genial, gregarious man with intellectual interests, he was generally well liked, even by his political opponents.
Seward was an uncompromising foe of slavery, and, although he apparently tempered his public expressions so as not to alienate votes, he nevertheless made two remarks that became catchphrases of the antislavery forces. Voicing his opposition to the Compromise of 1850 in the Senate, he said (March 11, 1850), “there is a higher law than the Constitution which regulates our authority over the domain.” In a speech at Rochester on Oct. 25, 1858, he declared that there would exist “an irrepressible conflict” until the United States became either all slave or all free.
With the disintegration of the Whig party, Seward and Weed joined (1855) the new Republican party. Prominent as he was, Seward, despite (or possibly because of) the efforts of Weed's machine, was never able to secure the Republican presidential nomination. His friendship toward immigrants, especially the Irish, alienated members of the former Know-Nothing movement within the Republican party.
Secretary of State
In 1861, Seward became Secretary of State under Abraham Lincoln, and many expected him to be the real power in the administration. He revealed his own desire to dominate the President in a peculiar memorandum (April 1, 1861) to Lincoln in which he proposed waging war against most of Europe so as to unite the nation. Seward also did some unwarranted meddling during the Fort Sumter crisis. After the Civil War broke out, however, he showed himself an able statesman, although it took all of Lincoln's ingenuity to keep both Seward and his rival, Salmon P. Chase, eternally ambitious for the presidency, in the same cabinet. Seward's handling of delicate matters of diplomacy with Great Britain, particularly in the Trent Affair, was notably adept. He also protested French intervention in Mexico and after the Civil War helped bring an end to it.
The plot of John Wilkes Booth to assassinate Lincoln also included a stabbing attack on Seward, but he recovered from his wounds and retained his cabinet position under the new President, Andrew Johnson. He supported Johnson's Reconstruction policy and, like the President, was roundly denounced by the radical Republicans. Seward's most important act in this administration was the purchase of Alaska from Russia in 1867. His foresight was not generally acknowledged, however, and Alaska was long popularly called “Seward's folly.” He also tried to purchase the two most important islands in the Danish West Indies (the Virgin Islands), but the Senate refused to approve his action.
See G. E. Baker, ed., The Works of William H. Seward (5 vol., 1853–84); F. W. Seward, ed., Autobiography . . . and Selections from His Letters (3 vol., 1891); biographies by Frederic Bancroft (1900, repr. 1967) and G. G. Van Deusen (1967).