In the nearly 250 years that the U.S. has been a country, only three of its presidents have been impeached.

In order to be impeached, a president must have committed “Treason, Bribery, or other high Crimes and Misdemeanors,” as outlined by the Constitution, although the document does not define what “high crimes and misdemeanors” may entail. Once solid grounds for impeachment are found, the House of Representatives then votes on the one or more articles of impeachment. If the majority of the House votes to impeach, the case is then carried forward to the Senate, where a trial is held. After the impeachment trial, the Senate votes as to whether or not they should convict the president. If two-thirds or more of Senators vote to convict the president, then the person is swiftly removed from office and replaced with the next in command. None of the three impeached presidents in U.S. history have been removed from office. Here are their stories.

Andrew Johnson (1868)

After President Abraham Lincoln’s assassination in 1865, his vice president, Andrew Johnson, succeeded him. A pro-Union Democrat, Johnson had made sure that his home state of Tennessee did not secede during the Civil War. Despite his patriotic actions, Johnson was incredibly racist, and was very lukewarm when it came to Reconstruction, or the rebuilding of the post-war Union, especially when it came to providing essential resources for displaced (mainly Black) southerners. Congress did not like him from the beginning.

The final straw, however, was his sudden replacement of Secretary of War Edwin Stanton, a man Lincoln himself had appointed and a member of the Radical Republicans, a subgroup of the Republican party which pushed for civil rights and liberties for freed African Americans (keep in mind, the Democratic and Republican parties had not switched names yet, and therefore Republicans circa this era would have had similar values as modern-day Democrats, and vice versa).

Congress argued that Johnson had violated the Tenure of Office Act and had found a replacement for Stanton without consulting Congress, and filed 11 acts of impeachment against him. He was impeached with a two-thirds majority in the House, and the case was moved to the Senate, where it failed. Later, in 1926, the Supreme Court ruled the Tenure of Office Act unconstitutional, destroying the entire case against Johnson.

Bill Clinton (1998)

In January 1998, President Bill Clinton’s affair with former White House intern Monica Lewinski became public, which Clinton vehemently denied ever participating in. As the investigation into the cover-up of the affair went on, however, Clinton admitted to his wrongdoings and articles of impeachment involving the obstruction of justice and perjury.

While Clinton was impeached, he was never removed from office due to the common conception that, while the president had committed misconduct, it simply was not enough to impeach him. That said, his offenses were not entirely forgiven. Said Republican Congresswoman Susan Collins, who voted against the conviction of Clinton, “In voting to acquit the President, I do so with grave misgivings for I do not mean in any way to exonerate this man.”

Historians and political analysts also believe that the plan to remove Clinton from office was flawed from the beginning, as public opinion began to swing in Clinton’s favor during the impeachment proceedings.

Donald Trump (2019 and 2021)

This year, President Donald Trump became the first U.S. president in history to be impeached twice.

The first time Trump was impeached was on the charges of abuse of power and obstruction of Congress following an investigation into a condemning phone call between Trump and the President of Ukraine, Volodymyr Zelensky. In the phone call, as well as a whistleblower’s testimony, it was revealed that Trump and his administration pressured Ukraine into investigating President Joe Biden’s son’s involvement with a Ukranian energy company. While these actions are not necessarily breaking the law, they do fall under the line “high Crimes and Misdemeanors” when it comes to the violation of public trust.

While Trump was impeached, the Senate acquitted him of all charges, with the casting of votes drawing on party lines. The only Republican senator to vote against Trump was Senator Mitt Romney of Utah. Many Republican senators who voted to acquit Trump argued that it should be up to the voters to decide on the following election day. And they did, with Trump joining the ranks of one-term presidents.

Not only is Trump the only president to have been impeached twice, but he may also be the first president to be impeached while he is out of office. On January 14, Trump was once again impeached by the House, this time with the charge of “incitement of insurrection” following the January 6 attack on the Capitol. Six days later, President Joe Biden was inaugurated, and Trump left the White House. Now it is up to the Senate to decide whether or not the impeachment should be followed-through. If it were to pass, it would mean that, while Trump is already out of office, he will no longer have the opportunity to run for reelection in 2024. And to many Americans, that is enough for them.