"Since 1870, numerous proposals have been introduced in Congress to establish permanent federal holidays. Eleven have thus far become law. Although these patriotic celebrations are frequently referred to as 'national holidays,' legally they are only applicable to federal employees and the District of Columbia. Neither Congress nor the President has asserted the authority to declare a 'national holiday' that would be binding on the 50 states, as each state individually determines its legal holidays. Creating a holiday for federal employees does, however, affect each state in a variety of ways, including the delivery of mail and conduct of business with federal agencies. Federal holidays have been created for a number of reasons. In several instances, Congress created federal holidays after a sizeable number of states created state holidays. In other instances, Congress took the lead. Additionally, each holiday was designed to emphasize a particular aspect of American heritage or to celebrate an event in American history."
CRS Report for Congress, R41990