On January 6, 2021, the United States Capitol in Washington, D.C. was attacked by a mob of supporters of President Donald Trump in an attempted self-coup, two months after his defeat in the 2020 presidential election. They sought to keep him in power by preventing a joint session of Congress from counting the Electoral College votes to formalize the victory of the president-elect Joe Biden. The attack was unsuccessful in preventing the certification of the election results. According to the bipartisan House select committee that investigated the incident, the attack was the culmination of a plan by Trump to overturn the election. Within 36 hours, five people died: one was shot by the Capitol Police, another died of a drug overdose, and three died of natural causes, including a police officer who died of a stroke a day after being assaulted by rioters and collapsing at the Capitol. Many people were injured, including 174 police officers. Four officers who responded to the attack died by suicide within seven months. Damage caused by attackers exceeded $2.7 million.
Called to action by Trump on January 5 and 6, thousands of his supporters gathered in Washington, D.C. to support his false claims that the 2020 election had been "stolen by emboldened radical-left Democrats" and demand that then-vice president Mike Pence and Congress reject Biden's victory. Starting at noon on January 6 at a "Save America" rally on the Ellipse, Trump gave a speech in which he repeated false claims of election irregularities and said "If you don't fight like hell, you're not going to have a country anymore". As Congress began the electoral vote count, thousands of attendees, some armed, walked to the Capitol, and hundreds breached police perimeters. Among the rioters were leaders of the Proud Boys and the Oath Keepers militia groups.
The FBI estimates 2,000–2,500 people entered the Capitol Building during the attack. Some participated in vandalism and looting, including in the offices of then-House speaker Nancy Pelosi and other Congress members. Rioters assaulted Capitol Police officers and journalists. Capitol Police evacuated and locked down both chambers of Congress and several buildings in the Complex. Rioters occupied the empty Senate chamber, while federal law enforcement officers defended the evacuated House floor. Pipe bombs were found at the Democratic National Committee and Republican National Committee headquarters, and Molotov cocktails were discovered in a vehicle near the Capitol. Trump resisted sending the National Guard to quell the mob. That afternoon, in a Twitter video, he restated false claims about the election and told his supporters to "go home in peace". The Capitol was cleared of rioters by mid-evening, and the electoral vote count was resumed and completed by the morning of January 7, concluding with Pence declaring the final electoral vote count in favor of President-elect Biden. Pressured by his cabinet, the threat of removal, and resignations, Trump conceded to an orderly transition of power in a televised statement.
A week after the attack, the House of Representatives impeached Trump for incitement of insurrection, making him the only U.S. president to be impeached twice. After Trump had left office, the Senate voted 57–43 in favor of conviction, but fell short of the required two-thirds, resulting in his acquittal. Senate Republicans blocked a bill to create a bipartisan independent commission to investigate the attack, so the House instead approved a select investigation committee. They held public hearings, voted to subpoena Trump, and recommended that the Department of Justice (DOJ) prosecute him. Following a special counsel investigation, Trump was indicted on four charges, which were all dismissed following his reelection to the presidency. Trump and elected Republican officials have promoted a revisionist history of the event by downplaying the severity of the violence, spreading conspiracy theories, and portraying those charged with crimes as hostages and martyrs.
Of the 1,424 people then charged with federal crimes relating to the event, 1,010 pled guilty, and 1,060 were sentenced, 64% of whom received a jail sentence. Some participants were linked to far-right extremist groups or conspiratorial movements, including the Oath Keepers, Proud Boys, and Three Percenters, some of whom were convicted of seditious conspiracy. Enrique Tarrio, then chairman of the Proud Boys, received the longest sentence, a 22-year prison term. On January 20, 2025, upon taking office, Trump granted clemency to all January 6 rioters, including those convicted of violent offenses.