The United States government system is a mixture of federal and state governments, with each having its own powers and responsibilities. According to the tenth amendment to the U.S. Constitution, any power not explicitly delegated to the federal government is reserved for the states or the people. So while the federal government is responsible for matters such as foreign policy, defense, interstate commerce, and the issuance of currency, individual states are responsible for matters such as education, law enforcement, and public health.