As historian David O. Stewart has noted, when Congress undertakes an impeachment process, it's like writing on water. There's so little guidance in the standards of impeachment, and legal precedent is thin on the ground. That said, there is a small body of legal history to reference — more, in any case, than the three presidential proceedings mentioned earlier. That's because U.S. presidents aren't the only ones who can be impeached. The impeachment provisions state that Congress can remove the president, vice president and all civil officers [source: U.S. House of Representatives].
In fact, while Andrew Johnson was the first president to be impeached, his was not the first impeachment trial. That (dis)honor belongs to one William Blount, senator of North Carolina who, in 1797 was believed to have provoked an American Indian rebellion in Florida to help the British. He managed to escape conviction, but nevertheless got expelled by a two-thirds vote from his fellow senators [source: U.S. House of Representatives].
Blount's case was the first of more than 60 impeachment proceedings undertaken by the House of Representatives since then. Fewer than a third of those proceedings ran their full course. The bulk of those— 15 in total — were trials of federal judges. Statistically, therefore, it makes sense that the eight impeachment proceedings that have resulted in actual convictions and removals have been those conducted against said federal judges for everything from drunkenness and tax evasion to accepting a bribe and perjury. Aside from three presidents, one senator and 15 judges, the House also once took on a cabinet secretary named William Belknap for corruption in 1876 [source: U.S. House of Representatives]. He was acquitted.
And of course, the U.S. isn't the only country to have impeachment provisions baked into its constitution. Many other countries adopted similar legislation when writing up their national laws, perhaps most notably Brazil. The South American country has the distinction of having impeached no fewer than two presidents in just 24 years. The first was in 1992 when Fernando Collor pulled a Nixon-style resignation before things got too hot for him. His reputation for corruption was so malodorous that few were sad to see him go. But Brazil's more recent 2016 trial of Dilma Rousseff has been far more divisive, leading to accusations that her opponents were carrying out a legal coup d'état. However, the trial did follow all of the established rules [source: The Economist]. One thing's for sure, as Ben Franklin would say, for all its faults, impeachment is a lot better than the alternative.