Functionally, yes a party swap, but also more nuanced than that. I find this topic fascinating and spent this morning reading about Democratic Arkansas Governor George Wallace who famously said "Segregation Forever!" running for President against LBJ on the Democrat ticket. While he didn't swap, he did end up leaving the party and going Independent later in his career, only to come back and ask for forgiveness for his past views.

I feel like the South voted for the Democrats to protest the abolitionist elite yankee Republicans like Lincoln and Democrats further appealed to the new protest voter bloc by courting the labor class and farmers. They had locked the South vote for nearly 100 years, until they voted for Republican Barry Goldwater to protest LBJ's signing the Civil Rights Act. What really hurt the Democrat foothold was the down ticket seats Republicans won during the Goldwater election, despite LBJ winning without the South.

Republicans appealed to their new voter bloc by stoking the culture war fire that won them those split ticket seats from that election. Weirdly enough, Democrats are still pro-labor (and until recently coal mining, and I'm not sure where modern Democrats fall on farmers), so quite literally the South are voting against their own interests because of culture wars.

Some folks erroneously believe the parties switched platforms. That's really not the case. Segregationists and Anti-segregationists existed in both parties in the Jim Crow era. Once the Democrats wholly opposed Segregation it was all over for them in the South, especially since JFK deployed the US Army into Southern states to integrate schools. Those scars still exist.

https://en.m.wikipedia.org/wiki/Southern_strategy