The story of Homeland Security Investigations (HSI) begins in 1789, when Congress established the U.S. Customs Service.

For over 100 years after it was founded, the U.S. Customs Service was the primary source of revenue for the government, inspecting and taxing goods imported into the United States. The funds generated helped pay for the country's early growth and infrastructure. Customs officials also stopped banned items from entering the country and used ships at sea to prevent smugglers from bringing items ashore. The list of banned items changed over time, but included undeclared liquor, tobacco, firearms, drugs, stolen property and other contraband.

In the 20th century, as international trade and travel increased dramatically, the Customs Service transitioned from an administrative bureau to a federal law enforcement agency. Customs officials still inspected goods entering and leaving the country, but Customs special agents increasingly used modern police methods to investigate criminals seeking to evade duties and profit from illegally smuggling contraband into and out of the United States. The 1976 Arms Export Control Act gave Customs the additional authority to investigate and prevent international weapons trafficking.

In 1933, Congress established the U.S. Immigration and Naturalization Service (INS). The Immigration Reform and Control Act of 1986 enhanced the responsibilities of the INS, granting the agency authority to investigate certain gang, fraud and human smuggling activities. The responsibilities and special agent footprint of the INS expanded even further in 1996, providing the agency additional authority and resources to investigate criminal offenses of U.S. immigration laws.

In the aftermath of the terrorist attacks on 9/11, Congress passed the Homeland Security Act of 2002, which established the Department of Homeland Security (DHS) as a stand-alone, Cabinet-level department to further coordinate and unify national homeland security efforts.

DHS opened its doors on March 1, 2003, and was created through the combination of all or part of 22 different federal departments and agencies into a unified Department. Two of those agencies combined within DHS were the U.S. Customs Service (formerly part of the Department of Treasury) and the INS (formerly part of the Department of Justice). The customs law enforcement responsibilities and investigations components of those two agencies formed the Offices of Investigations, Intelligence, and International Affairs within U.S. Immigration and Customs Enforcement.

In 2010, the Offices of Investigations, Intelligence, and International Affairs within U.S. Immigration and Customs Enforcement were combined into a new directorate within the agency known as Homeland Security Investigations, or HSI. Since that time, HSI has emerged as a premier U.S. federal law enforcement organization, with its agents on the front lines of the fight to protect the United States from global threats. Over the years, HSI has led some of the U.S. government’s most significant and consequential investigations, targeting and taking down drug cartels, money laundering syndicates, sanctions violators, torturers and war criminals, arms smuggling networks, human trafficking organizations, child exploitation networks, and a host of other actors that threaten the security of the United States.

Since its establishment, HSI has stayed true to its history and its roots but has continued to expand its footprint and operations. HSI has consistently met the needs of the time, evolving as global crime evolves; adapting to an ever-changing threat landscape; and embracing technology and innovation to enable us to combat the most significant threats to our country.

Over 200 years ago, our predecessors played a key role in imports, customs, and taxes. Today HSI serves as the principal investigative component of DHS and safeguards the American people and our homeland with honor, service, and integrity.