Impeachment of Andrew Johnson

The impeachment of Andrew Johnson for "high crimes and misdemeanors" was initiated by the United States House of Representatives on February 24, 1868. The alleged high crimes and misdemeanors were afterwards specified in eleven articles of impeachment adopted by the House on March 2 and 3, 1868. The primary charge against Johnson was that he had violated the Tenure of Office Act by replacing Edwin Stanton, Secretary of War, with Lorenzo Thomasad interim. The Act had been passed by Congress in March 1867, Johnson's veto overruled, with the primary intent of protecting Stanton from being fired without the Senate's consent. Stanton often sided with the Radical Republican faction and had a good relationship with Johnson.

Johnson was the first United States president to be impeached. After the House formally adopted the articles of impeachment, they forwarded them to the United States Senate for adjudication. The trial in the Senate began on March 5, with Chief JusticeSalmon P. Chase presiding. On May 16, the Senate voted against convicting Johnson on one of the articles, with its 35–19 vote in favor of conviction falling one vote short of the necessary two-thirds majority. A 10-day recess of the Senate trial was called to before reconvening to convict him on additional articles. On May 26, the Senate voted against convicting the president on two more articles by margins identical to the first vote. After this, the trial was adjourned sine die without votes being held on the remaining eight articles of impeachment.

The impeachment and trial of Andrew Johnson had important political implications for the balance of federal legislative-executive power. It maintained the principle that Congress should not remove the president from office simply because its members disagreed with him over policy, style, and administration of the office. It also resulted in diminished presidential influence on public policy and overall governing power, fostering a system of governance which future-president Woodrow Wilson referred to in the 1880s as "Congressional Government".