Attacks on the United States Congress

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 then 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. It is the only attempted coup d'état directed towards the Federal government in the history of the United States.

United Airlines Flight 93 was a domestic scheduled passenger flight that was hijacked by four Al-Qaeda terrorists on the morning of Tuesday, September 11, 2001, as part of the September 11 attacks. The hijackers planned to crash the plane into a federal government building in the national capital of Washington, D.C. The mission failed when the passengers fought back, forcing the terrorists to crash the plane in Shanksville in Somerset County, Pennsylvania, preventing them from reaching Al-Qaeda's intended target, but killing everyone aboard the flight. The airliner involved, a Boeing 757-200 with 44 passengers and crew, was flying United Airlines' daily scheduled morning flight from Newark International Airport in New Jersey to San Francisco International Airport in California, making it the only plane hijacked that day not to be a Los Angeles–bound flight.

British naval attack on the United States during the War of 1812

American far-left militant organization, 1969–77

mass shooting in Alexandria, Virginia, United States, on 14 June 2017

shooting by police of a man attempting to drive through a barricade at the US Capitol

attack on the US capitol by Puerto Rican nationalists