California - https://www.nhdca.org/
Maryland - https://www.mdhumanities.org/programs/maryland-history-day/
Minnesota - http://education.mnhs.org/historyday/state-history-day
Mississippi - https://www.usm.edu/history/national-history-day-instructional-materials
Florida - http://www.floridahistoryday.com/
North Carolina - https://www.ncdcr.gov/education/history-day/teachers
Pennsylvania - http://hsp.org/education/national-history-day