Andrew Johnson and Congress were having a power struggle over the different Reconstruction Acts and differing viewpoints of the south post-Civil War. Johnson being from the south, was in favor of going easy on them and not punishing them for starting the Civil War. The Congress predominantly made up of Radical Republicans wanted to punish the south and make it a long and difficult process for them to be reinstated into the United States. Congress feared that Johnson would gain too much power as president so they created the Office of Tenure Act, which stated that the president had to get Senate approval if he/she wanted to fire a Cabinet member. Johnson ignored this Act and fired someone in his cabinet without Senate approval, so ultimately ignored the law. Congress impeached him of breaking the law, and by one vote he was not convicted and remained president.
For Abraham Lincoln's relection in November of 1864, with an end of the Civil War in sight, he choose Andrew Johnson, a Southern Unionist, as his vice president. Lincoln's hope was having a southerner in the White House would ease the Reconstruciton of the United States and make the Federal Government seem more friendly in hopes of the Southern states return to the Union would go more smoothly.
When Lincoln was assassinated and Johnson became president the entire Congress, both the Senate and House of Representatives were all Republican as they were all Unionists. Johnson, although he did not believe in secession, was a Southern democrat and went against Lincoln's plan he he laid out prior to his death and Congress' belief that any Confederate officiers, judges, military or congressmen were not eligible for a presidential pardon. Johnson pardoned over 13,000 southerners that seceded from the Union.
Johnson continued his lenient southern strategy and pardon former confederates and transferred several of the district military commanders who had displayed Radical sympathies. Congress tried to impeach Johnson in early 1867 but the House did not believe the country should be subject to the shock of impeachment.
August 1867 Johnson deliberately violated the Tenure of Office Act. Stanton’s refusal to resign despite his disagreements with Johnson’s Reconstruction policy. So Johnson suspended Stanton while Congress was in recess.
February 1868 the Republican-dominated House passed 11 articles of impeachment. The first 8 articles focused on the charge that Johnson had unlawfully removed Stanton and had failed to give the Senate the name of a successor. Article 9 accused the president of issuing orders in violation of the Command of the Army Act.
The last 2 articles charged him with criticizing Congress of “inflammatory and scandalous harangue” (tirades). Article 11 also accused Johnson of “unlawfully devising and contriving” to violate the Reconstruction Acts, contrary to his obligation to execute the laws.
Senate trial began on March 5, 1868 and lasted till May 26th. Johnson’s attorneys would not allow his to plead his case in person.
Johnson worked behind the scenes to win over undecided Republican senators offering them a variety of political incentives.
Renegade Republicans explained for their controversial votes that
they feared damage to the separation of powers among the branches of government if Johnson was removed and they were assured by Johnson’s attorneys that he would stop obstructing congressional policy in the South. Republican senator, Edmund Ross from KS, believed that the office of the president would be degraded and ever after subordinated to the legislative will. (upheld the constitution)
His final act as president was to pardon confederate president Jefferson Davis.