On December 18, President Donald Trump was impeached by the House of Representatives.

On February 5, he was acquitted on both charges after a Senate trial.

Only three US presidents have faced impeachment — Andrew Johnson in 1868 and Bill Clinton in 1998 were both impeached, while Richard Nixon resigned before he could be impeached in 1974.

No president has ever been convicted. That hasn't changed.

Visit Business Insider's homepage for more stories.

President Donald Trump, the third president in history to be impeached, was acquitted on Wednesday.

In the fall, Congress investigated whether Trump pressured Ukraine to investigate his political rival, Democrat presidential candidate Joe Biden, and his son.

On December 13, the House Judiciary Committee voted to advance two impeachment articles against Trump — one for abusing his office, and the other for obstructing Congress. On December 18, he was impeached on both articles.

On February 5, he was acquitted on both charges. For the abuse of power charge, 48 senators, including Republican Sen. Mitt Romney, voted to convict Trump, while the other 52 Republican senators voted to acquit him.

For the obstruction of Congress charge, the final vote was along party lines — 53-47.

Impeachment is a power Congress has to remove presidents or other federal officials from office if enough lawmakers find that they have committed "treason, bribery, or other high crimes and misdemeanors."

First there's the investigation, then the House of Representatives votes on whether to impeach and charge them with any crimes, and if a majority votes in favor, then a Senate trial determines whether they're guilty and the penalty.

Three other presidents have faced impeachment proceedings.

In 1868, Andrew Johnson was impeached for breaching the Tenure of Office Act, but the Senate narrowly acquitted him by one vote. In 1974, Richard Nixon faced an impeachment inquiry, but he quit before he could be impeached. In 1998, Bill Clinton was impeached, but he was acquitted by the Senate.

Only 11 days had passed after a whistleblower complaint before Pelosi announced an impeachment inquiry, Axios reported. For Nixon, it took 599 days from the Watergate break-in to an inquiry, while for Clinton it took 260 days from the first news report of an affair to an inquiry.

Here's how the process went for the four presidents who faced impeachment.