In the months leading up to the 1864 election, Abraham Lincoln thought he would be a one term president. The war was taking longer than everyone had expected, and the mounting casualties made the Democratic Party message of a negotiated peace sound more appealing. The Republican Party was split between the Radical Republicans and the moderates. Some Republicans like Salmon P. Chase, Benjamin Wade, and Horace Greeley, opposed Lincoln's re-nomination on the grounds that he could not win. Chase had visions of becoming president himself.
For much of 1864, Lincoln himself believed he had little chance of being re-elected. Confederate forces had triumphed at the Battle of Mansfield, the Battle of the Crater, and the Battle of Cold Harbor and the war was continuing to take a very high toll in terms of casualties. During three months in the summer of 1864, over 65,000 Union soldiers were killed, wounded, or missing-in-action. In comparison, there had been 108,000 Union casualties in the first three years. The prospect of a long and bloody war started to make the idea of "peace at all cost" offered by the Democrats look more appealing.
It looked as if the war might even cause a split within Lincoln's own Republican Party. Senators Charles Sumner and Henry Wilson from Massachusetts wanted the Republican Party to advocate constitutional amendments to prohibit slavery and guarantee racial equality before the law. Not all northern Republicans supported such measures. Democratic leaders hoped that the radical Republicans would put forth their own ticket in the election. The New York World newspaper ran a series of articles encouraging supporters of General John C. Frémont in the hopes of damaging Lincoln's popularity.
Before the election, some War Democrats joined the Republicans to form the National Union Party, a coalition that supported the prosecution of the war. With the outcome of the war still in doubt, some political leaders, including Chase, Wade, and Greeley, opposed Lincoln's re-nomination on the grounds that they believed that he could not win. Chase put himself forward as the only candidate to contest Lincoln's re-nomination actively, but he withdrew in March when a number of prominent Republican officials, including some from Chase's own state of Ohio, endorsed Lincoln for re-nomination. Lincoln was still popular with most members of the Republican Party. The National Union Party nominated him for a second term as president at their convention in Baltimore, Maryland, on June 7-8, 1864. The party platform called for "pursuit of the war, until the Confederacy surrendered unconditionally; a constitutional amendment for the abolition of slavery; aid to disabled Union veterans; continued European neutrality; enforcement of the Monroe Doctrine; encouragement of immigration; and construction of a transcontinental railroad." It also supported the use of African-American troops and praised Lincoln's management of the war.
Andrew Johnson, the former senator from and current military governor of Tennessee, was named as Lincoln's vice presidential running-mate. He had been governor of Tennessee from 1853 to 1857 and was elected by the legislature to the Senate in 1857. When the Southern slave states, including Tennessee, seceded, he remained firmly committed to the Union. He was the only sitting senator from a Confederate state who did not resign his seat upon learning of his state's secession. In 1862, Lincoln appointed him as military governor of Tennessee after most of it had been recaptured. Lincoln hoped to send a message of national unity in his re-election campaign, especially to ensure the electoral votes of the border states.
But despite this support, Lincoln was still not optimistic about his chances for re-election. On August 23, Lincoln wrote the following:
“This morning, as for some days past, it seems exceedingly probable that this Administration will not be re-elected. Then it will be my duty to so co-operate with the President-elect as to save the Union between the election and the inauguration; as he will have secured his election on such ground that he can not possibly save it afterwards.”
Lincoln folded the note, sealed it, and asked the members of his Cabinet to sign the back of the paper without reading it. They did so.
The presidential election of 1864 was held on November 8th. In order to appeal to those who supported the war, the Democrats nominated General George B. McClellan as their candidate. Like the Republicans, the Democratic Party was also split between War Democrats and Peace Democrats. Moderate Democrats supported the war against the Confederacy, but they were now calling for a negotiated peace. Radical Peace Democrats known as Copperheads believed that the war was a failure. They favored an immediate end to the war. McClellan was seen as a strong candidate who could unify the party. The pro-war McClellan was selected as the party's candidate for president and anti-war Representative George H. Pendleton was selected as the party's candidate for vice-president.
An event known as the Radical Democracy Convention was held on May 29, 1864. General John C. Frémont, who had been the first presidential candidate for the Republican Party in 1856, was selected as their candidate. But Frémont withdrew from the race in September 1864. In his statement, Frémont declared that winning the Civil War was too important to divide the Republican vote. Although he still felt that Lincoln was not going far enough, the defeat of McClellan was of the greatest necessity. Frémont also brokered a political deal with Lincoln in which Lincoln removed Postmaster General Montgomery Blair from office.
Perhaps the thing that saved Lincoln's bid for re-election most was the fall of Atlanta on September 2. It turned out to be a September surprise, rather than an October surprise, but in those days news traveled a lot slower than it does today. On August 31, General William Tecumseh Sherman's army captured the railroad track from Macon top Atlanta. With his supply lines fully severed, Confederate General John Bell Hood pulled his troops out of Atlanta the next day, September 1, destroying supply depots as he left to prevent them from falling into Union hands. He also set fire to eighty-one loaded ammunition cars, which led to a conflagration watched by hundreds. The next day, on September 2, Mayor James Calhoun, along with a committee of leading formally surrendered the city. Sherman sent a telegram to Washington on September 3, reading, "Atlanta is ours, and fairly won". He then established his headquarters there on September 7, where he stayed for over two months. Later, after the election, on November 15, the army departed east toward Savannah for what became known as "Sherman's March to the Sea".
As September turned into October, the fall of Atlanta and the overall success of this military campaign were extensively covered by Northern newspapers, and were a boost to Northern morale and to President Lincoln's political standing. Suddenly the Democratic Party's call for negotiations with the Confederacy on the subject of a potential truce was not as popular. The capture of Atlanta and Hood's burning of military facilities as he evacuated showed that a successful conclusion of the war was in sight, weakening support for a truce. Republicans, under the banner of the National Union Party, campaigned on the slogan "Don't change horses in the middle of a stream." Many war Democrats joined them.
Only 25 states participated in the election, since 11 Southern states had declared secession from the Union. Three new states participated in a presidential election for the first time: Kansas, West Virginia, and Nevada. The reconstructed portions of Tennessee and Louisiana chose presidential electors, although Congress did not count their votes. Just for added measure, Lincoln arranged for leave for Union soldiers in those states where they were required to be physically present in the state to vote on election day. Lincoln received 2,218,388 votes (55.0%) and 212 electoral votes. McClellan received 1,812,807 votes (45.0%) and 21 electoral votes. McClellan won just three states: Kentucky, Delaware, and his home state of New Jersey. Lincoln won in every state he carried in 1860 except New Jersey, and also carried a state won four years earlier by Stephen Douglas (Missouri), one carried by John C. Breckenridge (Maryland) and all three newly admitted states (Kansas, Nevada and West Virginia). Soldiers were allowed to vote in the field if they came from the following states: California, Kansas, Kentucky, Maine, Michigan, Rhode Island, and Wisconsin. Out of the 40,247 army votes cast, Lincoln received 30,503 (75.8%) and McClellan 9,201 (22.9%).