The events of September 11, 2001, injected new urgency into INS’ mission and initiated another shift in the United States' immigration policy. The emphasis of American immigration law enforcement became border security and removing criminal aliens to protect the nation from terrorist attacks. At the same time the United States retained its commitment to welcoming lawful immigrants and supporting their integration and participation in American civic culture.
The Homeland Security Act of 2002 disbanded INS on March 1, 2003. Its constituent parts contributed to 3 new federal agencies serving under the newly-formed Department of Homeland Security (DHS):
Customs and Border Patrol (CBP),
Immigration and Customs Enforcement (ICE), and
U.S. Citizenship and Immigration Services (USCIS).
CBP prevents drugs, weapons, and terrorists and other inadmissible persons from entering the country. ICE enforces criminal and civil laws governing border control, customs, trade, and immigration. USCIS oversees lawful immigration to the United States and naturalization of new American citizens. Although now separate, these agencies continue to cooperate, benefitting from and building upon the legacy of INS.