After the war, Seymour made an unsuccessful run for Governor of Connecticut in 1849, but was elected governor by the Connecticut General Assembly the next year in 1850. He was re-elected in 1851, 1852 and 1853. He served as an 1852 presidential elector, endorsing Franklin Pierce and, in return for his support, Seymour was appointed to serve as minister to Russia and resigned the governorship shortly after being reelected to a fourth term. He accepted the commission of Minister to Russia from President Franklin Pierce. He resigned from the governorship on October 13, 1853, and spent the next four years in Russia, where he built a warm and ongoing alliance with the Czar Nicholas and his son. He served in this position until 1858 when President James Buchanan replaced him with Francis W. Pickens. In Russia, his attaches included Daniel Coit Gilman and Andrew Dickson White.