OK. I get that in 1853 we want a fort west of the Missouri to protect movement over the Oregon, California, and Santa Fe trails, and that someplace on the Kansas River has reliable water and is thus a good place to locate such a post. But even by 1870 Ft. Riley was largely obsolete: the cavalry fighting the Indian Wars of the 1870s were stationed at places like Ft. Larned and Ft. Hays. I understand that in 1884 Philip Sheridan named Ft. Riley "cavalry headquarters". (But wouldn't Ft. Hood have been better? Closer to Mexico and closer to the Gulf ports where the cavalry might actually be deployed?) And I understand that we didn't disband our horse cavalry until the late 1950s.
But why in the name of the One Who Is would anybody decide back in 1955 when the 1st Infantry Division was rotated out of Germany that it should go to Kansas? It's not as though Eisenhower wanted to go to Kansas itself. It's not as though the surrounding area is deserted enough to make a good large-scale life-fire exercise area. It's not as though Ft. Riley is centrally located to cheaply provide logistical support. It's not as though it is well-positioned to be deployed, well, virtually anywhere we might want to deploy it.
It's not as though the climate gives the soldiers stationed there soft-dollar compensation--either in summer of winter.