U.S. Immigration and Customs Enforcement was created by the Homeland Security Act of 2002 and began operations on March 1, 2003, as a bureau of the newly established Department of Homeland Security.1Public Law 107-296, Homeland Security Act of 2002. The agency was built from personnel and authorities pulled out of two older federal bodies, the Immigration and Naturalization Service and the U.S. Customs Service, and it took on their investigative and interior enforcement work as a single unit.
The Homeland Security Act of 2002
Congress passed Public Law 107-296 in November 2002 to consolidate the federal government’s security functions under one cabinet department. The law pulled together all or part of 22 separate federal departments and agencies, the largest government reorganization since the National Security Act of 1947 created the Department of Defense, the CIA, and the National Security Council. The stated goal was to end the fragmentation that had let overlapping agencies operate without sharing intelligence or coordinating enforcement.
Section 442 of the act created a bureau within DHS originally called the Bureau of Border Security, which would absorb investigative and enforcement divisions previously scattered across multiple departments. A reorganization plan modification, effective on the same day DHS opened its doors, renamed the bureau to the Bureau of Immigration and Customs Enforcement. The name was later shortened to U.S. Immigration and Customs Enforcement.
The Agencies ICE Replaced
Before DHS existed, the Immigration and Naturalization Service handled both immigration benefits (green cards, naturalization, asylum) and interior enforcement (arrests, detention, deportation). That dual mission produced constant tension between the service side and the policing side. The U.S. Customs Service, housed in the Treasury Department, focused on the movement of goods across borders: collecting duties, intercepting contraband, and investigating trade fraud. Both agencies also fielded uniformed inspectors at ports of entry, doing largely parallel work side by side.
The Homeland Security Act split those overlapping functions into three new agencies, each with a clearer mandate. U.S. Citizenship and Immigration Services took over the benefits side of the old INS, processing visa petitions, naturalization applications, and asylum claims. U.S. Customs and Border Protection absorbed the uniformed inspectors from both legacy agencies and became the single entity responsible for screening people and goods at ports of entry and patrolling the borders between them. ICE received the investigative and interior enforcement arms: the INS detention and deportation officers, the INS investigators, and the Customs Service’s criminal investigators. Section 471 of the act formally abolished the INS once all transfers were complete.
That inheritance is why ICE has always looked like two agencies fused into one. Its criminal investigative authority reaches across borders in a way that reflects the old Customs Service, while its detention and removal work carries forward what INS enforcement officers had done for decades.
March 1, 2003: ICE Begins Operations
DHS officially opened on March 1, 2003, and ICE stood up the same day. President George W. Bush appointed Michael J. Garcia as the first assistant secretary overseeing the new bureau. The logistical challenge was substantial. Thousands of employees from different agencies, with different pay scales, badge designs, reporting chains, and IT systems, had to be folded into a single organization practically overnight. Uniforms, credentials, and vehicle markings were updated to reflect the new identity, while administrative offices worked to align payroll, case management databases, and communication protocols across workforces that had been entirely separate.
The choice to launch on a single date, rather than phase the transfers in gradually, meant that ICE existed as a working agency from the moment DHS did. Cases already open at INS and the Customs Service moved with their agents; investigations did not pause for the reorganization.
What ICE Was Built to Do
ICE runs through two main divisions, and each one traces to a different legacy agency.
Homeland Security Investigations
Homeland Security Investigations, or HSI, is the investigative arm. Its roughly 6,000 special agents work out of 235 offices across the country and in locations abroad. HSI handles a wide range of cross-border criminal activity: human trafficking and smuggling, narcotics, weapons proliferation, money laundering, trade fraud, child exploitation, and cybercrime. The breadth of its portfolio reflects the combined investigative authority inherited from both the old Customs Service and the INS. Agents can pursue cases that involve people, goods, money, or data crossing international boundaries.
Enforcement and Removal Operations
Enforcement and Removal Operations, or ERO, manages the arrest, detention, and deportation of individuals who are in the country without authorization or who have been ordered removed. ERO runs detention facilities, manages a non-detained docket of people awaiting hearings, and operates fugitive operations teams that locate and arrest individuals with outstanding removal orders. ERO also administers the 287(g) program, which extends limited immigration enforcement authority to participating state, local, and tribal law enforcement agencies under ICE direction.
ICE Today
With an FY 2026 budget of roughly $11.3 billion and about 21,800 authorized positions, ICE ranks among the largest federal law enforcement agencies in the country. Its statutory authorities come mainly from Title 8 of the U.S. Code, which governs immigration and nationality, and Title 19, which governs duties, imports, and the movement of goods. Those two titles map onto the two halves of the agency’s origin: the immigration enforcement work it inherited from INS, and the customs enforcement work it inherited from Treasury.
What Congress created in 2002, and what opened its doors on March 1, 2003, was not a brand-new mission but a reorganization of enforcement authorities that had already existed for decades in other departments. The reorganization brought those authorities under one roof, under one chain of command, inside the department created to prevent another September 11.