Alfred P. Murrah Federal Building in the context of Oklahoma City National Memorial

The Federal Emergency Management Agency (FEMA) is an agency of the United States Department of Homeland Security (DHS), initially created under President Jimmy Carter by Presidential Reorganization Plan No. 3 of 1978 and implemented by two Executive Orders on April 1, 1979. The agency's primary purpose is to coordinate the response to a disaster that has occurred in the United States and that overwhelms the resources of local and state authorities. The governor of the state in which the disaster occurs must declare a state of emergency and formally request from the president that FEMA and the federal government respond to the disaster. The only exception to the state's gubernatorial declaration requirement occurs when an emergency or disaster takes place on federal property or to a federal asset—for example, the 1995 bombing of the Alfred P. Murrah Federal Building in Oklahoma City, Oklahoma, or the Space Shuttle Columbia in the 2003 return-flight disaster.

While on-the-ground support of disaster recovery efforts is a major part of FEMA's charter, the agency provides state and local governments with experts in specialized fields, funding for rebuilding efforts, and relief funds for infrastructure development by directing individuals to access low-interest loans, in conjunction with the Small Business Administration. In addition to this, FEMA provides funds for response personnel training throughout the United States and funds for non-federal entities to provide housing and services for migrants released from Department of Homeland Security custody.

Domestic terrorism or homegrown terrorism is a form of terrorism in which victims "within a country are targeted by a perpetrator with the same citizenship" as the victims. There are various different definitions of terrorism, with no universal agreement about it.

Unlike domestic terrorism, state terrorism is that perpetrated by nation states, but is not considered such by the state conducting it, making legality a grey area.

On April 19, 1995, American anti-government extremists Timothy McVeigh and Terry Nichols detonated a makeshift bomb stored in a rental truck parked near the Alfred P. Murrah Federal Building in Oklahoma City, Oklahoma in an act of domestic terrorism. The bombing remains the deadliest act of domestic terrorism in U.S. history, killing 167 people, injuring 684, and destroyed more than a third of the building, which was later demolished due to its structural instability following the attack. The blast destroyed or damaged 324 other buildings and caused an estimated $652 million worth of damage. The Federal Emergency Management Agency (FEMA) activated 11 of its Urban Search and Rescue Task Forces, consisting of 665 rescue workers. During rescue operations after the bombing, a rescue worker was killed after being struck on the head by falling debris, bringing the total death toll to 168.

Within 90 minutes of the explosion, McVeigh was stopped by Oklahoma Highway Patrolman Charlie Hanger for driving without a license plate and arrested for illegal weapons possession. Forensic evidence quickly linked McVeigh and Nichols to the attack; Nichols was arrested soon after the forensics linked him to the bombing, and within days, both men were charged. Michael and Lori Fortier were later identified as accomplices. McVeigh, a veteran of the Gulf War, rented a Ryder truck, which he later filled with the explosives used in the attack. Nichols had assisted McVeigh in planning the attack, and in making the bomb. McVeigh and Nichols were primarily motivated by their anger at the U.S. federal government, particularly its handling of the law enforcement sieges at Ruby Ridge in 1992 and Waco in 1993, as well as the 1994 Federal Assault Weapons Ban. McVeigh had timed the retaliatory attack to coincide with the second anniversary of the end of the siege in Waco and the Battles of Lexington and Concord, the first engagements of the American Revolution.