National Union Party (United States) in the context of 1864 presidential election

Moderate Republicans were a faction of American politicians within the Republican Party from the party's founding before the American Civil War in 1854 until the end of Reconstruction in the Compromise of 1877. They were known for their loyal support of President Abraham Lincoln's war policies and opposed the more militant stances advocated by the Radical Republicans. According to historian Eric Foner, congressional leaders of the faction were James G. Blaine, John A. Bingham, William P. Fessenden, Lyman Trumbull, and John Sherman. Their constituencies were primarily residents of states outside New England, where Radical Republicanism garnered insufficient support. They included "Conservative Republicans" and the moderate Liberal Republicans, later also known as "Half-Breeds".

During the 1864 United States presidential election, amidst the backdrop of the ongoing Civil War, moderate Republicans supported merging the Republican Party with the War Democrats (Democrats who supported the continuation of the Union war effort) to form the National Union Party alliance. At the Republican National Convention (which operated under the name of the "National Union National Convention" that year), they spearheaded the effort to replace Lincoln's vice president Hannibal Hamlin with Tennessee Democrat Andrew Johnson, acting out of the belief that placing a War Democrat on the presidential ticket would solidify support to ensure Lincoln's re-election.

Andrew Johnson (December 29, 1808 – July 31, 1875) was the 17th president of the United States, serving from 1865 to 1869. The 16th vice president, he assumed the presidency following the assassination of Abraham Lincoln. Johnson was a War Democrat who ran with Lincoln on the National Union Party ticket in the 1864 presidential election, coming to office as the American Civil War concluded. Johnson favored quick restoration of the seceded states to the Union without protection for the newly freed people who were formerly enslaved, as well as pardoning ex-Confederates. This led to conflict with the Republican Party-dominated U.S. Congress, culminating in his impeachment by the House of Representatives in 1868. He was acquitted in the Senate by one vote.

Johnson was born into poverty and never attended school. He was apprenticed as a tailor and worked in several frontier towns before settling in Greeneville, Tennessee, serving as an alderman and mayor before being elected to the Tennessee House of Representatives in 1835. After briefly serving in the Tennessee Senate, Johnson was elected to the U.S. House of Representatives in 1843, where he served five two-year terms. He was the governor of Tennessee for four years, and was elected by the legislature to the U.S. Senate in 1857. During his congressional service, he sought passage of the Homestead Bill, which was enacted soon after he left his Senate seat in 1862. Slave states in the Southern U.S., including Tennessee, seceded to form the Confederate States of America, but Johnson remained firmly with the Union. He was the only sitting senator from a Confederate state who did not promptly 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 retaken. Johnson was a logical choice as Lincoln's running mate in 1864 because Lincoln wanted to send a message of national unity in his re-election campaign. Following their victory, Johnson became vice president.

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.

Andrew Johnson was the 17th president of the United States from April 15, 1865, after the assassination of President Abraham Lincoln, to March 4, 1869. The 17th president, Johnson was a member of the Democratic Party before the Civil War and had been Lincoln's 1864 running mate on the National Union ticket, which was supported by Republicans and War Democrats. Johnson took office as the Civil War came to a close, and his presidency was dominated by the aftermath of the war. As president, Johnson attempted to build his own party of Southerners and conservative Northerners, but he was unable to unite his supporters into a new party. Republican Ulysses S. Grant succeeded Johnson as president.

Johnson, who was himself from Tennessee, favored quick restoration of the seceded states to the Union. He implemented his own form of Presidential Reconstruction – a series of proclamations directing the seceded states to hold conventions and elections to re-form their civil governments. His plans did not give protection to the former slaves, and he came into conflict with the Republican-dominated Congress. When Southern states returned, many of their old leaders passed Black Codes to deprive the freedmen of many civil liberties, congressional Republicans refused to seat legislators from those states and established military districts across the South. Johnson vetoed their bills, and congressional Republicans overrode him, setting a pattern for the remainder of his presidency.

Presidential elections were held in the United States on November 3, 1868. In the first election of the Reconstruction Era, Republican nominee Ulysses S. Grant defeated Horatio Seymour of the Democratic Party. It was the first presidential election to take place after the conclusion of the American Civil War and the abolition of slavery. It was the first election in which African Americans could vote in the reconstructed Southern states, in accordance with the First Reconstruction Act.

Incumbent president Andrew Johnson had succeeded to the presidency in 1865 following the assassination of Abraham Lincoln, a Republican. Johnson, a War Democrat from Tennessee, had served as Lincoln's running mate in 1864 on the National Union ticket, which was designed to attract Republicans and War Democrats. Upon accession to office, Johnson clashed with the Republican Congress over Reconstruction policies and was impeached and nearly removed from office. Johnson received some support for another term at the 1868 Democratic National Convention, but, after several ballots, the convention nominated Seymour, who had formerly served as Governor of New York. The 1868 Republican National Convention unanimously nominated Grant, who had been the highest-ranking Union general at the end of the Civil War. The Democrats criticized the Republican Reconstruction policies, and "campaigned explicitly on an anti-black, pro-white platform," while Republicans campaigned on Grant's popularity and the Union victory in the Civil War.