<P> Impeachment in the United States is an enumerated power of the legislature that allows formal charges to be brought against a civil officer of government for crimes alleged to have been committed . Most impeachments have concerned alleged crimes committed while in office, though there have been a few cases in which Congress has impeached and convicted officials partly for prior crimes . The actual trial on such charges, and subsequent removal of an official upon conviction, is separate from the act of impeachment itself . Impeachment proceedings have been initiated against several presidents of the United States . Andrew Johnson and Bill Clinton are the only two presidents to have been successfully impeached by the House of Representatives, and both were later acquitted by the Senate . The impeachment process against Richard Nixon was never completed, as Nixon resigned his office before the vote of the full House for impeachment, but such a vote was widely expected to pass, and the threat of it and a subsequent conviction in the Senate was the impetus for Nixon's departure . To date, no president has been removed from office by impeachment and conviction . The impeached official continues in office until conviction . </P> <P> Impeachment is analogous to indictment in regular court proceedings; trial by the other house is analogous to the trial before judge and jury in regular courts . Typically, the lower house of the legislature impeaches the official and the upper house conducts the trial . </P>

Who was the last president of the us to be impeached