In its over 200-year history, the U.S. Capitol has been the primary place where the Senate and the House of Representatives pass the country’s laws and where presidents are inaugurated and deliver their annual State of the Union addresses. But while the Capitol was built to house legislative governance, it has also been the site of violence in multiple forms.

Construction of the Capitol formally began on September 18, 1793, when President George Washington laid the first cornerstone. Enslaved Black people performed the actual construction of the Capitol. Congress began using the building in 1800, the year the federal government moved its operations from Philadelphia to Washington, D.C. Like many of the first federal buildings in D.C., the Capitol’s design was based on 19th-century neoclassical style, inspired by ancient Greek and Roman architecture.

The Capitol’s construction continued until the War of 1812, when the country’s wartime mobilization forced it to a halt. A year into the conflict between the United States and the British Empire, American troops set fire to a capitol in colonial Canada. In retaliation, British troops in 1814 burned federal buildings in Washington, D.C.—including the White House and the Capitol.

The fire didn’t completely destroy the Capitol, but it damaged enough of it that some members of Congress suggested relocating the federal government back to Philadelphia or find another city. Instead, workers rebuilt the Capitol and continued to expand it as the number of states—and their representatives in Congress—grew. (Today, it covers over 1.5 million square feet and has more than 600 rooms.) Over the next few decades, interactions between these congressmen became increasingly strained and violent.

The U.S. antebellum period was characterized by violence against enslaved Black people, free Black people and abolitionists. It was a period in which anti-slavery newspapers faced mob violence, and the issue of slavery drove congressmen to attack one another.

One of the most famous incidents of congressional violence is the caning of Charles Sumner. In 1856, pro-slavery Representative Preston Brooks beat anti-slavery Senator Charles Sumner nearly unconscious with a cane on the Senate floor. Brooks said he chose to attack Sumner this way because he didn’t want to break an 1839 law against congressional dueling, passed a year after a congressman had killed another in a duel in Maryland.

The caning of Sumner was not an isolated incident. Historian Joanne B. Freeman identified more than 70 violent occurrences between congressmen while researching her book, The Field of Blood: Violence in Congress and the Road to the Civil War. In 1858, a fistfight between about 30 congressmen broke out in the House of Representatives at 2:00 a.m. when a southerner grabbed a northerner by the throat. In 1860, pro-slavery congressmen threatened an anti-slavery congressmen with pistols and canes while he spoke against slavery on the House floor.

When Abraham Lincoln won the presidency in 1860, southern states responded by seceding and waging war on the Union. Southern congressmen who had once worked in the Capitol began fighting against the Union it stood for—though during the Civil War, the Confederate Army never captured D.C.

In addition to duels and physical fights between congressmen, non-members of Congress have fired weapons or planted bombs on the Capitol grounds.

On July 2, 1915, a former German professor at Harvard, Erich Muenter, planted a package containing three sticks of dynamite in the Capitol near the Senate Reception room. The explosive detonated around midnight and during a time when the Senate had been on recess. An on-duty Capitol Police officer was nearly knocked out of his chair during the blast, but fortunately no one was injured. The German-born man later wrote a letter to a Washington, D.C. newspaper saying he had planted the explosives to protest U.S. wartime aid to Britain and said he hoped the detonation would "make enough noise to be heard above the voices that clamor for war.” He then traveled to the home of J.P. Morgan Jr. (son of the famous financier) in Long Island, New York and shot him. Morgan’s wounds proved superficial and he survived. Muenter was soon captured and detained in jail where, several days later, he died by suicide.

On March 1, 1954, four Puerto Rican Americans fired guns in the House of Representatives, injuring five congressmen. The attackers said they acted to demand independence for the U.S. territory of Puerto Rico. (Puerto Ricans have U.S. citizenship but can’t vote for president and have no voting representatives in Congress.) The injured congressmen survived, and the four shooters received prison sentences. President Jimmy Carter commuted one of their sentences in 1977, and granted clemency to the other three in 1979.

On March 1, 1971, a bomb exploded in the Capitol building. While the explosion did not injure anyone, it caused some $300,000 in damage. A group calling itself the Weather Underground claimed to be behind the bombing and said it was in protest of the ongoing U.S.-supported bombing of Laos.

Thirteen years later, on November 7, 1983, a bomb tore through the second floor of the Senate wing of the Capitol. The device detonated late in the evening and no one was harmed, but it caused an estimated $250,000 in damage. A group calling itself the Armed Resistance Unit later claimed responsibility for the attack, saying it was in retaliation for military actions in Grenada and Lebanon. Seven people were eventually arrested in connection with the attack.

Political causes aside, individuals have committed acts of violence on Capitol grounds through the decades. These incidents include an 1890 fatal shooting sparked by a feud between a reporter and a former congressman and a 1998 fatal shooting of two Capitol Police officers in 1998 by a man who claimed the U.S. was plagued by cannibalism and a fictional disease.

On January 6, 2021, when representatives met to formalize the presidential election results, a mob of rioters supporting President Donald Trump and seeking to deny President-Elect Joe Biden’s electoral victory pushed through police barricades and stormed the Capitol, some smashing windows to enter its halls. A protester who was shot by police died in the chaos, and approximately 6 law enforcement officers were assaulted, according to a March 7, 2022 report from the U.S. Government Accountability Office.