After the breakup of the Whig Party in the early 1850s , he briefly joined the American Party before becoming a member of the Republican Party . He was a candidate for president at the 1860 Republican National Convention , but Lincoln won the party 's nomination . Bates was appointed as attorney general in 1861 , at the start of the American Civil War . He successfully carried out some of the administration 's early war policies , but he objected to the Emancipation Proclamation and resigned from the Cabinet in 1864 after being passed over for a Supreme Court appointment . After leaving office , he unsuccessfully opposed the adoption of a new state constitution in Missouri
1860 Republican National Convention
1860 Republican National Convention
Edward Bates