US Citizenship and Immigration Services (USCIS) is a government agency in the United States responsible for overseeing lawful immigration to the country. It manages the process of granting U.S. citizenship, issuing green cards, and processing various immigration applications and petitions. USCIS aims to ensure that immigration laws are followed while providing services to immigrants and their families. The agency also plays a crucial role in promoting national security and preventing fraud in the immigration system. USCIS conducts background checks and interviews to assess applicants' eligibility for immigration benefits, ensuring that those who enter the country meet legal requirements.