## Overview Federal law enforcement in the United States refers to the constellation of agencies and personnel responsible for enforcing federal laws, maintaining national security, and ensuring public safety across the country. Unlike state or local police, these agencies operate under the authority of the federal government, addressing crimes and threats that transcend state boundaries, such as terrorism, cybercrime, drug trafficking, and immigration violations[1][5]. The United States is home to over 80 federal law enforcement agencies, each with specialized missions, but all unified by their commitment to upholding federal statutes[6]. ## What Federal Law Enforcement Does Federal law enforcement agents investigate crimes, collect evidence, apprehend suspects, and assist in prosecutions within the federal justice system[2]. Their responsibilities are diverse: the Federal Bureau of Investigation (FBI) tackles complex crimes and national security threats, the Drug Enforcement Administration (DEA) focuses on narcotics, and the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) regulates and investigates offenses involving those commodities[1][7]. Agencies under the Department of Homeland Security (DHS), such as U.S. Customs and Border Protection (CBP) and the Transportation Security Administration (TSA), secure borders, airports, and critical infrastructure[1]. Other agencies, like the U.S. Fish and Wildlife Service, enforce environmental laws, while the U.S. Secret Service protects national leaders and investigates financial crimes[6]. ## History The roots of federal law enforcement trace back to the early republic, with the U.S. Marshals Service—established in 1789—being the oldest federal law enforcement agency[1]. The FBI was created in 1908, originally to investigate antitrust and banking crimes, and has since evolved into the nation’s premier investigative agency[1]. The modern landscape was reshaped after the September 11, 2001 attacks, leading to the creation of DHS in 2002, which consolidated several agencies to better combat terrorism and enhance