Background. Donald Trump is the third U.S. president to be impeached by the House of Representatives, after Andrew Johnson in 1868 and Bill Clinton in 1998. Before Trump, Johnson was the only president to be impeached in his first term. The House Judiciary Committee also voted to adopt three articles of impeachment against Richard Nixon, but he resigned prior to the full House vote.

https://en.wikipedia.org/wiki/First_impeachment_of_Donald_Trump