This federal holiday began in 1940 as "I Am An American Day", a day for the recognition of American citizens.
In 1952, Congress repealed this holiday and legislated for the creation of "Citizenship Day", which also included the commemoration of the signing of the Constitution. The new law encouraged civil and educational authorities to arrange observances of the day and instruct citizens in their rights and responsibilities.
In 2004, Congress renamed the day "Constitution Day and Citizenship Day". It also introduced the requirement that "each educational institution that receives Federal funds for a fiscal year shall hold an educational program on the United States Constitution on September 17 of such year for the students served by the educational institution" (Public Law 108-477, Consolidated Appropriations Act of 2005).
More information on Constitution Day and Citizenship Day is available from the website of the Law Library of Congress.