I think that it should be in the curricula of every high school in America:  A field trip to Washington, D. C.  Really.  I would recommend the sophomore year, maybe as part of an American History class or Civics class (do they even still call it that?)

The normal 'touristy' places should be on the itinerary:  The Washington Monument, The White House, The Smithsonian(s), The Lincoln Memorial, etc.

And then there are the places that should be treated with reverence, reflection, and deep respect:  The Vietnam Memorial, The Marine Memorial, Arlington National Cemetery, and The Tomb of The Unknown Soldiers.

Less than 20% of the soldiers that volunteer for the "Old Guard", the military unit responsible for guarding the tomb, are accepted into the training program, and, of those, a tiny fraction actually pass muster.  These volunteers are 'squared-away', as they need to be.  Just by browsing through this website, you can see the dedication it takes to be one of the Sentinels on the Tomb of the Unknowns.

Fox News did this piece on The Tomb of The Unknowns during Hurricane Irene.

(Via Fox News)