1797-1801

Restrictive laws known as the Alien and Sedition Acts were passed during the administration of President John Adams.

1861–1865

During the American Civil War, the administration of President Abraham Lincoln suspended the right to the writ of habeas corpus.  Approximately 38,000 civilians were detained by the military.

1865 or 1866

The Ku Klux Klan was founded in the United States in Pulaski, Tennessee, by former Confederate general Nathan Bedford Forrest and other upper-class Southerners.

1870s

The Molly Maguires, a secret organization of Irish coal miners in Pennsylvania, committed acts of sabotage and terrorism against mining companies.

1882–1968

Nearly 5,000 African Americans (mostly men) died when they were lynched by mobs or smaller groups of white Americans.

1919

The first Red Scare occurred when a series of bombs were detonated and letter bombs were intercepted.  Anarchists and Communists were accused of the bombing campaign

September 1920

A bomb was detonated on Wall Street in New York City. Thirty-five people were killed, and hundreds were injured.

1930s

The second Red Scare occurred. 

1938

The House Un-American Activities Committee was formed to investigate allegations of subversion.

1940

The Smith Act was passed, making advocacy of the violent overthrow of the government a Federal crime.

1941-1945

The administration of President Franklin Delano Roosevelt established a War Relocation Authority and the U.S. Army was tasked to move ethnic Japanese to internment facilities on the West Coast and elsewhere.  More than 100,000 ethnic Japanese, approximately two-thirds of whom were American citizens, were forced to relocate to the internment facilities. 

1950s

The third Red Scare occurred, when Republican Senator Joseph McCarthy of Wisconsin held a series of hearings to counter fears of spying by Communist regimes, primarily China and the Soviet Union.  The hearings reflected and encouraged a general fear that Communists were poised to overthrow the government and otherwise subvert the “American way of life.”

November 1, 1950

Two Puerto Rican nationalists attempted to assassinate President Harry Truman at Blair House in Washington, D.C.

March 1965

Members of the United Klans of America shot to death Viola Liuzzo in Alabama and wounded a traveling companion.

October 1969

A bomb in Chicago destroyed a monument dedicated to the Chicago police. The leftist Weatherman group was responsible for the attack.

1970s

The Weathermen—renamed the Weather Underground Organization—committed at least 40 bombings

Mid-1970s

The leftist Symbionese Liberation Army (SLA), a violent terrorist cell, gained notoriety for several high-profile incidents.

1970s

The Black Liberation Army was suspected to have committed a number of attacks in New York and California. They were thought to have been responsible for numerous bombings, ambushes of police officers, and bank robberies.

1975-1983

The Puerto Rican independencista group Armed Forces for National Liberation (Fuerzas Armadas de Liberación Nacional, or FALN) was responsible for approximately 130 bombings.

1978–1995

During a 17-year FBI manhunt, Theodore Kaczynski, also known as the Unabomber, killed 3 people and injured 22 in a series of bombings.

May 1981

A Brinks armored car was robbed in Nyack, New York, by former members of the Weather Underground Organization, Students for a Democratic Society, Black Panther Party, the Republic of New Africa, and the Black Liberation Army.

April 1983

A neo-Nazi group calling itself the Order initiated a campaign of violence, hoping to foment a race war in the United States.

August 1992

Hurricane Andrew struck the United States, causing an estimated $26 billion in damage.  The Federal response was widely criticized as unnecessarily slow and uncoordinated.

February 1993

In the first terrorist attack on the World Trade Center, a large vehicular bomb exploded in a basement parking garage; it was a failed attempt to topple one tower into the other.

1994-1996

The Aryan Republican Army (ARA) operated in the Midwest and robbed 22 banks in seven states.

April 19, 1995

The Alfred P. Murrah Federal Building was bombed in Oklahoma City, Oklahoma, by rightist extremists.

April 24, 1996

During the administration of President Bill Clinton, the United States passed its first comprehensive counterterrorism legislation, entitled the Anti-Terrorism and Effective Death Penalty Act. The purpose of the Anti-Terrorism Act was to regulate activity that could be used to mount a terrorist attack, provide resources for counterterrorist programs, and punish terrorism.

January 1997

A bomb was detonated in Atlanta, Georgia, at a family health clinic that provided abortion services. A second bomb was detonated soon thereafter.

January 16, 1997

Two bombs exploded at an abortion clinic in Sandy Springs, Georgia. The Army of God was suspected.

August 7, 1998

Two car bombs exploded at the U.S. embassies in Nairobi, Kenya, and Dar es Salaam, Tanzania, killing more than 250 and wounding about 5,000.

August 19, 1999

A mass shooting by two teenagers at Columbine High School in Littleton, CO, resulted in 13 dead and 21 wounded.

September 11, 2001

Terrorists hijacked four airliners. Two of the planes were crashed into the twin towers of the World Trade Center in New York City, causing them to collapse. One plane was crashed into the Army section of the Pentagon building. The final plane crashed into rural Pennsylvania.

October 26, 2001

President George W. Bush signed new anti-terrorist legislation into law. It was labeled the “Uniting and Strengthening America by Providing Appropriate Tools Required to Intercept and Obstruct Terrorism Act of 2001,” commonly known as the USA PATRIOT Act. 

Late 2001

Letters containing anthrax were sent through the U.S. postal system in the New York and Washington, DC, areas.

May 2002

The U.S. Department of Justice expanded the FBI’s surveillance authority. New guidelines were promulgated that permitted field offices to conduct surveillance of religious institutions, Web sites, libraries, and organizations without an a priori (before the fact) finding of criminal suspicion.  A broad investigative net was cast using the rationale that verifiable threats to homeland security must be detected and preempted.

August 2005

Hurricane Katrina struck the Gulf Coast of the United States causing nearly 2,000 deaths and billions of dollars in destruction.  The Federal response was strongly criticized as unacceptably inadequate and ponderous.  State emergency response authorities in Louisiana were also widely criticized as images of thousands of refugees were broadcast globally.

The U.S. Department of Justice’s inspector general released an extensive report that revealed that FBI agents had complained repeatedly since 2002 about harsh interrogations conducted by military and CIA interrogators.

June 1, 2009

In Little Rock, Arkansas Abdulhakim Mujahid Muhammad, opened fire at an armed forces recruiting office, killing Army Private William Long wounding Private Quinton Ezeagwula.

November 5, 2009

At the Fort Hood military base in Killeen Texas, Army Major Nidal Malik Hasan, shot and killed 13 people and wounded at least 30.  He was an army psychiatrist.

December 25, 2009

Umar Farouk Abdulmutallab, a Nigerian national, attempted to detonate an explosive compound hidden in his underwear aboard an aircraft flying from Amsterdam to Detroit.

May 1, 2010

Times Square in New York City was evacuated after the discovery of a car bomb.

April 25-28, 2011

More than 350 tornadoes struck in the United States, the largest recorded tornado outbreak in history.  During the outbreak, on April 27 an EF4 tornado struck the Tuscaloosa-Birmingham Alabama area.  Its path of destruction stretched more than 80 miles and over 60 people were killed.

May 2, 2011

Al Qaeda founder Osama bin Laden was killed during a raid by U.S. Navy SEAL commandos in Abbottabad, Pakistan.

October 2012

“Superstorm” Sandy struck the United States’ eastern seaboard.  The hurricane came ashore in the densely populated urban northeastern region of the United States, causing widespread damage.

December 14, 2012

At Sandy Hook Elementary School in Newtown Connecticut, 20 children and 6 adults were killed by gunman Adam Lanza.

April 15, 2013

Two bombs were detonated at the crowded finish line of the Boston Marathon.  Three people were killed and more than 260 were wounded, many severely.

May 20, 2013

An EF5 tornado with wind velocity exceeding 200 miles per hour touched down near Moore Oklahoma.  Hundreds of residents were injured and 23 were killed.

June-July 2013

the British newspaper The Guardian published a series of articles reporting covert surveillance operations coordinated by the U.S. National Security Agency (NSA).  The operations involved the acquisition of European and U.S. telephone metadata and Internet surveillance.

September 16, 2013

A mass shooting occurred at the Washington Navy Yard in Washington, D.C., in which lone gunman Aaron Alexis shot and killed 12 people before being shot and killed by police.