This isn't true at all. The name "Sprint" wasn't chosen until the 70s and the initial business was alternative long-distance carrier, not a railway cell phone.
Mea culpa, searching for the actual original name “Southern Pacific Railroad Internal Network Telecommunications” pulls up a number of interesting stories about the origins of the company running telegraph lines along the rail tracks.
Example: https://www.npr.org/2012/10/15/162963607/sprint-born-from-ra...
However I do not see anything resembling cell phone service happening until the 1970s.
See: https://www.battlecreekenquirer.com/story/news/2022/05/23/je...