Answer:
On July 27, 29, and 30, 1974, the Committee approved three articles of impeachment against Nixon, for obstruction of justice, abuse of power, and contempt of Congress, and reported those articles to the House of Representatives. ... With his political support completely eroded, Nixon resigned from office on August 9, 1974. He wasn't actually impeached though
But Andrew Johnson was.....
The impeachment of President Andrew Johnson was the result of political conflict and the rupture of ideologies in the aftermath of the American Civil War. ... The Tenure of Office Act, passed over Johnson's veto in 1867, stated that a president could not dismiss appointed officials without the consent of Congress.
Also Clinton
The impeachment of Bill Clinton was initiated on October 8, 1998, when the United States House of Representatives voted to commence impeachment proceedings against Bill Clinton, 42nd president of the United States, for "high crimes and misdemeanors", which were subsequently detailed in two articles of impeachment.