Sheridan named the military post in memory of Sill .
In 1869 , Sill 's West Point classmate and division commander , General Philip H. Sheridan , officially established a military post in the Wichita Mountains of Oklahoma .
General named the military post in memory of Sill .
In 1869 , Sill 's West Point classmate and division commander , General Philip H. Sheridan , officially established a military post in the Wichita Mountains of Oklahoma .