Impeachment of President Johnson in 1868 fails by a single vote in the Senate

The first US President to be impeached was Andrew Johnson, who came to power after the assassination of Lincoln and bought Alaska from Russia.

Johnson was locked in a protracted conflict with Congress, but the impeachment was set in motion over the President's unfounded attempts to dismiss the Secretary of War, Edwin Stanton, which the Senate had stood in the way of.

In 1868 the House of Representatives began impeachment proceedings and a majority voted "for", but in the Senate, whose vote actually decides the President's fate, one vote was lacking to reach the necessary two thirds, and Johnson remained President.

The second to undergo impeachment proceedings was Bill Clinton. As for now, we wait to see what becomes of Trump, since the Republicans, who support him, hold the majority in the Senate, and for his removal 20 Republican senators would have to vote "for", which is highly unlikely.