United States Constitution Day is September 17 of each year. Congress enacted legislation requiring all public schools to set aside one day during the week of September 17 to teach all students about the U.S. Constitution and about citizenship.
Consult these resources for ideas:
Constitution Day Webinar: http://vimeo.com/75903601
Center for Civic Education: http://new.civiced.org/resources/curriculum/constitution-day-and-citizenship-day
C-SPAN: http://www.c-spanclassroom.org/Members/Constitution-Clips.aspx
National Archives: http://www.archives.gov/education/lessons/constitution-day/
History of the Iowa Constitution http://www.statelibraryofiowa.org/services/collections/law-library/iacon/prevcon
National Endowment for the Humanities http://edsitement.neh.gov/constitution-day
National Council for the Social Studies: http://www.socialstudies.org/resources/constitution
Library of Congress: http://www.loc.gov/teachers/constitutionday.html