FORT SILL, OKLAHOMA -- The old quadrangle was an especially hectic place for the close of business on Tuesday.
Hundreds of regular Army and Army brass gathered to hold what's called a Retreat Ceremony.
But before the bugle sounded and the flag came down, 150 soldiers re-enlisted and re-affirmed their proud service.
Then Fort Sill's latest in a very long line of Commanding Generals, Wilson Shoffner, trained everyone in the work of the hour.
"Ses....Que...Centennial," he pronounced with the audience. "There. Now you're trained."
150 years is easier to say but a long time in coming.
It was during the winter campaign of 1869 that General Phillip Sheridan chose this spot to build a fort near the Medicine Bluffs.
This cavalry installation's first mission was subduing and removing the last of the Plains Native Americans.
The first structures were picket style cottonwood logs.
Buffalo Soldiers from the all black 10th Cavalry built the limestone block houses still in use.
"This is the most complete Indian Wars era fort of original structure still in existence," says Fort Sill Museum Director Frank Siltman.
He also says this fort and its soldiers have been involved in every major American conflict since.
"We really have historic preservation by accident and so all these structures have been preserved."
A change from cavalry to artillery, new weapons, new tactics, same old ground.
General Sheridan had a friend at West Point who died in a Civil War battle.
Brigadier General Joshua Sill's name is still on soldier's lips even as the bugle blows and the cannon fires the retreat of another day.
The last of the old Indian forts on the Southern Plains remains active serving both history and the modern military.
The official 150th anniversary of Fort Sill is January 8th, 1869.
The original name of the Fort was Camp Wichita.
For more information on fort history and how to visit the museum go to http://sill-www.army.mil/