President Donald Trump will soon become the third president in American history to face impeachment by the House – and it’s all because of what he did on July 25.

That’s the day he spoke on the phone with Ukrainian President Volodymyr Zelensky and pressed him to investigate Democrats, including former Vice President Joe Biden, a leading 2020 rival. House Democrats are poised to cast historic votes this month impeaching Trump, triggering a Senate trial.

The public is still learning new information about what happened on July 25, which was just a day after special counsel Robert Mueller testified to Congress about the Trump campaign’s contacts with Russia in the 2016 election. As Trump moved on from that scandal, he waded right into another one. Democrats say the July 25 timeline provides a damning account of presidential abuses of office. Trump maintains his behavior was “perfect.”

Here’s a minute-by-minute breakdown of one of the most consequential days in modern US political history. All times are listed in Washington time, though some key players were in Ukraine.