A more thorough explanation:

The Immigration and Naturalization Service (INS) was a government agency that was responsible for regulating border patrol activities, enforcing immigration laws, and supervising the immigration process. It was established in 1933 by President Franklin D. Roosevelt and was initially under the U.S Department of Labor (DOL). In 1940, it became an agency under the U.S Department of Justice (DOJ).

In 2002, Congress passed the Homeland Security Act, which led to the end of INS in 2003. It was replaced with three new agencies: Immigration and Customs Enforcement (ICE), Customs and Border Protection (CBP), and U.S. Citizenship and Immigration Services (USCIS).

ICE is responsible for enforcing and removing individuals who are in the country illegally. CBP is in charge of border security to prevent illegal entry, transnational crimes, and terrorism. USCIS is the federal government agency that offers national immigration services to all applicants who want to live or study in the U.S. For example, individuals who apply for a green card must file a petition with USCIS.

Overall, INS was an agency that played a crucial role in regulating immigration in the United States. Its responsibilities have now been divided among three different agencies, each with its own specific focus and responsibilities.