Arlington Becoming Crowded Ground?

It's one of the oldest traditions in this tradition-rich graveyard. Just before Memorial Day, one flag is placed exactly one foot in front of every tombstone in Arlington National Cemetery — all 220,000 of them.

Only this year, because of the war, Arlington is running short of soldiers to put the flags in, CBS News Correspondent Jim Stewart

. And, the cemetery is also slowly but surely running out of ground to bury them.

The pace is now 27 funerals a day. If the pace of burials picked up, how quickly would Arlington fill up?

"At the projected rate of burial today, on the land we already have, we have room for approximately 20 more years," Arlington's historian, Tom Sherlock, told Stewart.

Actually it could be less than two decades if trends continue.

Twice the percentage of Iraqi War dead are being buried here than Vietnam War dead. And WWII vets are rapidly passing away. Families will wait for weeks.

"They look out over 624 acres and they just see hero after hero after hero and their loved one becomes, you know, knitted into the American fabric," Sherlock said.

And nowhere is that fabric richer. The place was already full of heroes from a mass grave for the Battleship Maine to Medal of Honor winner Audie Murphy, when President Kennedy's burial sent demand soaring 400 percent.

So, that makes Arlington the military burial ground of choice, given the prestige involved and time and convenience of getting there?

"That is true," Sherlock said.

That wasn't always the case.

Great stretches of Arlington are filled with unknown soldiers from the Civil War — including a fair number of Confederate dead. Memorials for most part are simple markers. General of the Armies John J. Pershing asked for nothing more than a plain marble slab — the "G.I. Issue Stone," he called it.

But it wasn't always equal treatment. In the old days they used to plant the officers on the high ground and the enlisted got the low ground.

"Actually that was the only segregation we've had at Arlington — that was between officers and enlisted men," Sherlock said.

Now, of course, there is no distinction. The dead are all equal. And day after day they muster here for the last time … waiting for entry into America's most exclusive hallowed ground.