On the practical side, many of the national cemeteries are becoming over crowded. I would propose that after 100 years of internment, that the remains be cremated and the urn placed in a memorial hall.
I know that some would find this offensive, but at some point in time, the space is going to need to be managed. A cut off date of 1915 would be a cut off prior to WWI.
Nobody would suppose the space was going to last forever at any rate; has there been consideration of opening extension cemeteries?
There is ALWAYS land around to start another burial ground. Use part of the Fed Park lands.
Dig them up?
Ever hear of revered ground?
A much better solution IMO is Arlington II.
My uncle was KIA on Siapan and they brought him back to his home town American soil which was appropriate, but digging up those how have served just because they are running out of space is bizarre in my opinion.
Another national cemetery is the only thing that makes sense to me...
I know that some would find this offensive, but at some point in time, the space is going to need to be managed. A cut off date of 1915 would be a cut off prior to WWI.
If you see 5000 grave markers in a National Cemetery there are likely 8000-9000 persons buried there. I'll explain why. VA Cemeteries use a one plot Vet & Spouse policy. IOW they stack Vet & Spouse in the same grave.
The demand for VA plots has about peaked with the passing of WW2 Vets. Many Vets both in war & peace time serving 180 days active duty or more do not realize they qualify for burial in one.
My state and the VA did a joint venture where 50 plus acres were bought about 5 years ago. My dad was among the first 40 buried there. Two months ago my wife was buried in the same cemetery. Family cost was about $700 for the grave opening, closing, vault, and head stone. As well they handed me a deed to the plot itself. My burial minus funeral home cost will be free. Mom will share dads grave and I will share my wife's grave when my time comes.
The local National Cemetery established by General Burnside lasted from The Civil War till early 1980's then a new one opened. It filled up except for spouse burials about 4 years ago. Most were WW2 Vet, Korea, and Nam.
Arlington is an exception in policy because it is considered an Honors Cemetery although any National Cemetery or joint operated VA/State Veterans Cemetery can designate an area solely for Honor and/or KIA's.
Realistically National & Veterans Cemeteries a very small percentage of grave yards. I'd guess and say Veteran Cemeteries in number are likely less than 1% vs private ones owned by corporations, churches, families, etc.