Federal policy oversees and regulates immigration to the United States and citizenship of the United States. The United States Congress has authority over immigration policy in the United States, and it delegates enforcement to the Department of Homeland Security. Historically, the United States went through a period of loose immigration policy in the early-19th century followed by a period of strict immigration policy in the late-19th and early-20th centuries. Policy areas related to the immigration process include visa policy, asylum policy, and naturalization policy. Policy areas related to illegal immigration include deferral policy and removal policy.
