The oldest Federal Museum is the West Point Museum. The Museum began at least in the 1830s and was open to the public two years before the Smithsonian, by then Superintendent Robert E. Lee, in 1854. For the rest of the 19th century The National Museum of the US Army was the Museum at West Point. Then Rock Island Arsenal in 1903, and after World War I the Army opened a Museum at Chateau Thierry after World War I Much of that museum was moved to the US in the 1930s. After World War II when literally shiploads of captured Japanese and German weapons were shipped to the US (one ship carried over 5000 Japanese Ni mortars)The Army began looking for ways to use up this stuff. The Center of Military History was born and every Army base in the world had a collection. As bases closed those collections were sent to the Center of Military History’s depots. Every base in Germany after the Cold War had its museum closed and collections shipped to DC for example. This one is just the newest and state of the art. The Museum Support Center they are showing off is the repository for all the US Army Museums that are still open. At last count there are something like 60 of them. The West Point Museum, The Infantry Museum, The Armor Museum, Airborne Special Ops, Patton Museum are just the bigger ones. So this collection DOES get seen. As another commenter pointed out, no museum can show ALL of it’s collection ALL of the time. There isn’t space and it’s not good for the objects. But no one is hiding it away. In fact most of that can be seen at any of a number of military museums not just US Army museums. Lastly there are two things I’d like to point out. That swivel gun, appears to be the Rappahannock Forge Wall gun. Rappahannock Forge is the earliest known American gun maker. The gun is exceedingly rare but not one of a kind. There are four, the US Army has all four, the one shown at the Support Center, West Point Museum, Rock Island Arsenal and Springfield Arsenal.