Constitution Day is observed in Puerto Rico every July 25, commemorating the approval of the Constitution of Puerto Rico in 1952. This public holiday marks the day when Governor Luis Muñoz Marín proclaimed the constitution, which came into effect following its ratification by an electorate referendum on March 3, 1952. The holiday was established on August 4, 1952, replacing Occupation Day, which remembered the landing of American troops in Puerto Rico on July 25, 1898. Constitution Day celebrates Puerto Rico's status as a Commonwealth and acknowledges its historical transition from Spanish rule to American governance. The observance highlights the significance of the constitution in shaping Puerto Rico's political landscape.