Article II, Section 4:
The President, Vice President and all civil Officers of the United States, shall be removed from Office on Impeachment for, and Conviction of, Treason, Bribery, or other high Crimes and Misdemeanors.
The post-bellum experience in American history saw a variety of government officials impeached on a number of different grounds. These examples provide important principles that guide the practice of impeachment through the present day. For example, the Senate has not always conducted a trial following an impeachment by the House. In 1873, the House impeached federal district judge Mark. H. Delahay for, among other things, drunkenness on and off the bench.1 The impeachment followed an investigation by a subcommittee of the House Judiciary Committee into his conduct.2 Following the House vote on impeachment, Judge Delahay resigned before written impeachment articles were drawn up and the Senate did not hold a trial.3 The impeachment of Judge Delahay indicates that the scope of impeachable behavior is not limited to strictly criminal behavior; Congress has been willing to impeach individuals for behavior that is not indictable, but nonetheless constitutes an abuse of an individual's power and duties.
This period of American history was fraught with partisan conflict over Reconstruction.4 In addition to President Johnson, a number of other individuals were investigated by Congress during this time for purposes of impeachment. For example, in 1873, the House voted to authorize the House Judiciary Committee to investigate the behavior of Edward H. Durrell, federal district judge for Louisiana.5 A majority of the House Judiciary Committee reported in favor of impeaching Judge Durell for corruption and usurpation of power, including interfering with the state's election.6 Judge Durrell resigned on December 1, 1874 and the House discontinued impeachment proceedings.7
The first and only time a Cabinet-level official was impeached occurred during the presidential administration of Ulysses S. Grant. Grant's Secretary of War, William W. Belknap, was impeached in 1876 for allegedly receiving payments in return for appointing an individual to maintain a trading post in Indian territory.8 Belknap resigned two hours before the House unanimously impeached him,9 but the Senate nevertheless conducted a trial in which Belknap was acquitted.10 During the trial, upon objection by Secretary Belknap's counsel that the Senate lacked jurisdiction because Belknap was now a private citizen, the Senate voted 37-29 in favor of jurisdiction.11 A majority of Senators voted to convict Secretary Belknap, but no article mustered a two-thirds majority, resulting in acquittal. A number of Senators voting to acquit indicated that they did so because the Senate did not have jurisdiction over an individual no longer in office.12 Notably, although bribery is explicitly included as an impeachable offense in the Constitution, the impeachment articles brought against Secretary Belknap instead charged his behavior as constituting high crimes and misdemeanors.13 Bribery was mentioned at the Senate trial, but it was not specifically referenced in the impeachment articles themselves.14