The law mandating Constitution Day programming appears as a section of an appropriations act: Consolidated Appropriations Act, 2005, Public Law 108-447. The Constitution Day and Citizenship Day measure appears in 118 Stat. 2809, 3344-45 (Section 111).
The measure changing the name from Constitution Day to Constitution Day and Citizenship Day appears in the United States Code (36 U.S.C. §106).
The Notice of Implementation appeared in the Notices section of the Federal Register, May 24, 2005 (70 FR 29727).