Andrew Johnson was the first U.S. president to be impeached in 1868.

Andrew Johnson was impeached for abuse of power, specifically for violating the Tenure of Office Act, which prohibited the president from removing certain government officials without the consent of the Senate.

Three presidents have been impeached in U.S. history: Andrew Johnson, Richard Nixon, and Bill Clinton.

Donald Trump was the first president to be impeached twice, in 2019 and 2021.

Richard Nixon was impeached for obstruction of justice, specifically for his role in the Watergate scandal.

Bill Clinton was impeached for perjury and obstruction of justice, specifically for lying under oath about his relationship with Monica Lewinsky.

Andrew Johnson was acquitted in both of his impeachment trials, in 1868 and 1869.

Richard Nixon resigned from office in 1974 before he could be impeached by the House of Representatives.

Donald Trump was impeached in 2019 for abuse of power and obstruction of Congress.

Donald Trump was impeached in 2021 for inciting an insurrection at the U.S. Capitol on January 6, 2021.

The constitutional process for impeaching a president begins with a vote in the House of Representatives.

After a president is impeached by the House of Representatives, the Senate holds a trial to determine whether to convict the president and remove them from office.

The maximum penalty that can be imposed on a president who is convicted in an impeachment trial is removal from office.

The historical significance of political impeachments in the United States is that they have led to the removal of presidents from office.

Some of the common themes that emerge from the history of political impeachments in the United States include abuse of power, obstruction of justice, bribery, and perjury.