This happened in my neck of the woods where I grew up and still live next to, on Fort Hood.

So Camp Hood was put in once Pearl Harbor happened and the US entered the War. The Army policy at the time was to have integrated busses for soldiers to travel to recreational areas in surrounding cities. However, the army due to exploding demand contracted out local bus lines and drivers to provide services to soldiers at the brand new base. Circa 1940s, the surrounding area consisted of mostly rural areas and very small railroad and farm towns like Killeen, which of course this is the South and the Cotton Belt built on slavery, too. You can still see the former Cotton Gin in downtown Belton about 20 minutes away.

Jackie was a newly minted college educated officer in the 761st Tank Battalion, a segregated unit of all black tankers that would earn the nickname "Black Panthers". He definitely understood his basic civil rights and self-worth as a human being. The local bus driver told him to give up a seat for a white servicemember, and he refused not just because it wasn't right ethically, but the Army regulations said he shouldn't have to. Sadly, he was still arrested by MPs that were called, and a Court-Martial was threatened. His original commander refused to file the charges, and the chain of command decided to transfer him to another unit whose commander agreed to. The NAACP and other national organizations heard about this case and quickly built up pressure on the DoD to stop the process, which helped the charges to be reduced, but he still had to go to court. Thankfully, the all white jury found him not guilty, and he was quickly transferred away from the 761st to Kentucky.