The United States Marine Corps acts as the initial military respondent, via air or sea, to international disaster scenes and threats to U.S. interests.

Compared to the other four military branches, the Marine Corps history offerings are decidedly limited. However, a small selection of resources may be relevant for K-12 education.

A interactive timeline breaks the history of the Marines down into periods under different leaders, major innovations, and battles in which the corps has participated. The official site also offers back issues of Marines magazine, beginning with 2005.

If you are interested in the social history of the Marines, brief descriptions of their major symbols or their lore are the best resources available. Note that some features are covered in both sections.

A national museum of the Marine Corps also exists in Triangle, VA, if a field trip is in store. Tours are not offered, but the website does make gallery worksheets available.

The mission of the U.S. Air Force is to provide global air, space, and cyber intelligence, defense, and attack capabilities to the United States of America.

While all of the military branch sites seem to scatter the their historical information widely within their sites, this navigational difficulty is perhaps most pronounced on the Air Force sites. That said, the offerings could easily be applied in the classroom as early elementary activities through detail or visual aids for teaching military history in later high school.

Maybe you want to brush up on your own military history knowledge? If that's the case, your best bets are the short overview of Air force history; a collection of online history full-text books and pamphlets; or the suggested reading list, originally intended for airmen.

Short on time or looking for texts to share with your students? Try the speech transcripts from the past year, which may be useful for comparison to historical ideologies; online history essays and articles; or the brief overviews of popular topics, including aviation, WWI, WWII, Korean War, and Vietnamese Conflict history.

Other resources of note include lesson plans and teaching resource guides; a means of contacting historians, librarians, and volunteers who can answer specific questions; and a heritage page with focal sections on individual periods of time and a "this week in history" feature. Each time period link on the right side of the heritage page leads to relevant biographies, aircraft overviews, historical milestone lists, photographs, and artworks. Note that clicking on "more" for photos and artworks will take you to general image galleries, while the "more" function for people, technology, and milestones provides only information relevant to the selected range of time. The general image galleries, including history subsections, are divided into photograph and art options.

Finally, if you live near Dayton, OH, you could plan a trip to the National Museum of the U.S. Air Force. For those of you not in the area, the museum offers a virtual tour via podcast.

The United States Navy, one of five national military branches, is responsible for the preparation and maintenance of maritime vessels and troops to be deployed in the defense of the United States and marine freedom.

Although an initial glance at the official Navy website does not suggest that the department offers educational materials, the site provides a wide variety of resources which could be put to good use in the history classroom. These include modern Navy photographs and both print and web advertisements for comparison to historical photographs, recruitment posters, and insignia within the Naval Heritage and History Command's Online Library. The library also presents Naval biographies and a selection of online reading, which includes Naval abbreviations and period regulations.

If you desire more information on 20th-century Naval life or action, a good starting point would be the archives of Naval Aviation News, with back issues from 1943 to present, or All Hands Magazine, with issues from 1922 to present day.

Other online resources include art exhibits, short essays related to Naval artifacts, and the Little Skippers page. The latter contains a lesson plan, latitude and longitude activity, and word search.

If you are looking for field trip opportunities, the Navy maintains the official National Museum of the United States Navy, which houses exhibits of U.S. Naval history, covering topics from polar exploration to military actions and navigation. The DC Naval Yard also holds the early history (1776-1919) and operational archives. Visitors unable to reach the Washington Naval Yard, may find the list of other official U.S. Naval museums useful.