Middle school students (grades 6–8) participate in the Junior Division, and high school students (grades 9–12) participate in the Senior Division. Within these divisions, there are nine competitions, including Essay, Exhibit, Documentary, Performance, and Website, among others. Every year, the national organizers identify a broad theme related to the history of the United States. 

The Historical Society of Pennsylvania hosted National History Day Philadelphia at the National Constitution Center in 2024. Nearly 200 students participated in the competition on March 6 (Junior Division) and March 7 (Senior Division). The theme was “Turning Points,” intended to invite students to consider questions of time and place, cause and effect, change over time, and impact and significance. Among the year’s bright spots, Saint Mary Interparochial School performed exceptionally well in the Junior Division, with two students winning first place in the Website competition for their digital platform, "Jack Mullin: Man of Sound." Similarly, 7th-grade students won first place in the Documentary competition for their short film, Willowbrook: A Scandal for Change. Both teams were invited to participate in the Pennsylvania state championship in May.  

The theme for 2025 is “Rights and Responsibilities." The Connelly Foundation committed $50,000 to the Pennsylvania Historical Society for the competition in Philadelphia and to the Chester County Historical Society for the competition in Chester and Delaware counties. Students will once again delve into the past, discovering its richness and complexity, and sharing their newfound knowledge.