The new marker actually replaced an older one, which can also be seen below. I've written a blog post about the older marker.
Over the life of this blog I've written a number of posts about Pelham; you can find a list here.
A few further comments are below.
The name was changed from Shelbyville to Pelham sometime after the Civil War ended, although exactly when and by whom are not known. John Pelham was born in Jacksonville, Alabama, and is buried there.
However, the name Pelham appears on an 1876 map of the state and in an 1880 city of Birmingham directory.
Current state highway maps distributed at welcome centers and rest stops along the Interstates include a community named Pelham in the northeastern corner of Choctaw County. I have been unable so far to locate any information about this place. Google Earth doesn't show much there but houses, trees and roads; perhaps I'll drive down one day and check it out.
Here's the original marker, which had the same text on both sides. The date of installation in the lower right is hard to read but appears to be 1976.