Radical Democratic Party (United States) in the context of 1864 presidential election

Presidential elections were held in the United States on November 8, 1864, near the end of the American Civil War. Incumbent President Abraham Lincoln of the National Union Party easily defeated the Democratic nominee, former General George B. McClellan, by a wide margin of 212–21 in the electoral college, with 55% of the popular vote. For the election, the Republican Party and some Democrats created the National Union Party, especially to attract War Democrats.

Despite some intra-party opposition from Salmon Chase and the Radical Republicans, Lincoln won his party's nomination at the 1864 National Union National Convention. Rather than re-nominate Vice President Hannibal Hamlin, the convention selected Andrew Johnson of Tennessee, a War Democrat, as Lincoln's running mate. John C. Frémont, who had been the Republican nominee in 1856, started to run as the nominee of the new Radical Democratic Party, with War Democrat John Cochrane as Frémont's running mate; the new party criticized Lincoln for being too moderate on the issue of racial equality, but Frémont and Cochrane withdrew from the race in September and their new party dissolved. The Democrats were divided between the Copperheads, who favored immediate peace with the Confederacy, and War Democrats, who supported the war. The 1864 Democratic National Convention nominated McClellan, a War Democrat, but adopted a platform advocating peace with the Confederacy, which McClellan rejected, although his running mate George H. Pendleton wrote it. While the Confederacy seemed to have survival potential in summer 1864, it was visibly collapsing by election day in November.

The 1864 National Union National Convention was the United States presidential nominating convention of the National Union Party, which met in Baltimore, Maryland on June 7 and 8, 1864. National Union was the name adopted by the main faction of the Republican Party in a coalition with many, if not most, War Democrats and Unconditional Unionists after some Republicans and War Democrats nominated John C. Frémont over Lincoln a few weeks earlier. The National Union renominated Abraham Lincoln for president and Andrew Johnson was nominated for vice president. During the Convention, the party adopted a platform calling for a victorious end in the ongoing Civil War, the eradication of slavery by constitutional amendment and the enforcement of the Emancipation Proclamation.