Permit a couple comments about the soldiers who guard The Tomb.
They are members of the 3rd Infantry (Regiment), "The Old Guard," the oldest regiment in the United States Army. They (and similar units of the other branches) perform ceremonial duties in MDW (Military District of Washington).
The selection process for membership in The Old Guard is challenging and for the guards of The Tomb, it is extremely daunting, requiring not only the highest level of military precision, but impeccable character and dedication.
Training to guard The Tomb includes endless hours of drill and mastery of the manual of ams. At Fort Myer, there is a tennis court with a long rubber mat that matches the one by The Tomb. Aspiring sentinels get to march back and forth on that for several weeks before taking a shift at The Tomb (at night, for starters).
They guard The Tomb 24/7, regardless of weather. A few years ago, severe weather was forecast for Washington (blizzard, hurricane, something bad like that) and the guards were given the option of standing down. Of course they declined.
I have observed the transition from Springfield '03 rifles to M-1's to the current M-14, always carried on the shoulder away from The Tomb. Nothing else has changed. Never will.
As it should be.
(Some other time I will explain the proper use of challenge coins, but not here, not now.)