Under the “division of power,” system in the United States there are different levels of law and law enforcement. Some laws and law-enforcement agencies are at the federal or national level. Some are at the state level. (Examples of the 50 states that comprise the United States are Texas, California, and Florida.) Still others are at the county or local level.

Immigration laws come mainly under the jurisdiction of the Department of Homeland Security, which was formed following the September 11 attacks.

Law at all these levels are expected to be in agreement with the American Constitution, which is the foundational document for all American government.

Americans say they operate under the "rule of law." Laws, rules, and regulations presumably apply equally to everyone, whatever their position in the society. The general idea is that everyone must obey laws and regulations, without exceptions based on wealth, “connections,” or political or social position. Chinese may also say they operate under a rule of law, but they also have the idea that there is a “back door” way to virtually any objective. Americans do not have the “back door” idea in the way Chinese do.

Lawyers play a major role in American society, which places great emphasis on written laws, rules, regulations, and procedures. Students may need a lawyer if they encounter legal problems.