The United States consists of 50 states, the District of Columbia (a special area that is the home of the federal government), the territories of Guam, American Samoa, and the U.S.Virgin Islands, and the commonwealths of the Northern Mariana Islands and Puerto Rico.

The United States is a nation governed by laws. Government officials make decisions based on those laws.The Constitution is known as the “supreme law of the land” because every citizen, including all government officials, and every law that is created must uphold the principles of the Constitution. Laws apply equally to everyone.The federal government has limited powers. Powers not given directly to the federal government by the Constitution are held by the states.

Federal immigration law determines whether a person is an alien, and associated legal rights, duties, and obligations of aliens in the United states. The United States has a long history of immigration laws. Congress has total and complete  authority over immigration. Power of the President is limited to policies on refugees. Unless the issue concerns the rights of aliens to constitutional protections the courts have rarely intruded.