The most socially conscious Berry song is undoubtedly Promised Land, which if people know their history and the time in which it was written was an obvious commentary on the Freedom Riders. Every stop in the song refers to something specifically from that brutal trip through the south.
This is the first I've heard of this theory. The song mentions Houston, Albuquerque, and Los Angeles. The first verse says "California on my mind." I think the mention of Birmingham, New Orleans, etc. may be coincidental here. Where did you get this idea?
The Freedom Rides (of which there were many, but these were the first highly publicized ones taking place prior to when Berry wrote this, while serving time in prison for the bogus Mann Act charge) followed very specific routes as does his song, not only in checking off the stops accurately, but also describing to a T the reaction in those places. The first Freedom Ride started in Washington, whereas his started his Norfolk, Virginia, (very close and careful to obscure the political nature of the song, however from that point forward the exact route is detailed) “we stopped in Charlotte, but bypassed Rock Hill and never was a minute late"
(through Virginia and North Carolina there was no trouble, including at the first stop in Charlotte and things looked smooth until crossing into SC where the first bus was assaulted in the terminal at Rock Hill. The second bus, a Trailways line, which Berry is clearly referring to, avoided trouble by meeting with local sympathetic people who spirited them away from the now-locked terminal, hence the line “bypassed Rock Hill”). Rock Hill is not exactly a big city he'd be likely to pluck off a map of the south, nor would he, in the early 60's, have ridden a public bus through the south himself, especially that area of the south, to be referring to his own personal experience. The only time Rock Hill was nationally known was for two very ugly racial incidents, of which this was the most famous.
He then continues: “We were 90 miles out of Atlanta by sundown rolling through the Georgia state”
(it was here they met with Martin Luther King Jr. in real life). “We had more trouble that turned into a struggle halfway across Alabam"
(specifically Anniston, Alabama… and I’d say racists burning the bus after forcing it to the side of the highway qualifies as a “struggle”, wouldn’t you?) "and that ‘hound
(Greyhound bus) broke down and left us all stranded in downtown Birmingham”
(that’s precisely where the original Freedom Ride ended because no bus would take them further, they were literally stranded and in a dire situation, as RFK, then Secretary Of State, was trying to get them a plane to Louisiana and wishing the whole thing would just go away). That’s when the Nashville group, SNCC, spearheaded by Diane Nash, sent replacements to Birmingham to pick up the freedom ride. They were totally unaffiliated with the first Freedom Ride, but obviously were sympathetic to it and their joining it and picking up where the original Freedom Riders were forced to quit and carrying on with it is what turned it into a full-fledged successful movement.
Now Chuck takes over from that point, building the rest of the song from those original facts and fictionalizing the rest in allegorical fashion, as the best songwriters always tend to do. The Promised Land, of course, is freedom itself, as represented by the airplane and California, though both of those have nothing to do with the actual course of events in the Freedom Rides themselves, though alternative transportation to New Orleans does. But Berry had done this type of thing before, disguising his true intent so the records would be played by white outlets. He did it most famously in Brown Eyed Handsome Man, using “eyes” as opposed to “skin” as the distinguishing characteristic, but the intent is clear, and then again in Johnny B. Goode, where his original lyric was “lived a colored boy named Johnny B. Goode”, but he made it “country boy” so it’d be devoid of controversy.
There is absolutely no way that those major plot points, as accurate as if Walter Cronkite was reporting them, were coincidental, especially coming from someone as intelligent as Chuck Berry. It was a thinly veiled protest commentary. If you haven't read "Freedom Riders" by Raymond Arsenault or seen the PBS documentary on the Freedom Rides, I highly recommend both. In the book Berry's song is recounted in two different points and in the endnotes they go into detailed analysis of the precise similarities between his lyrics and the actual events.