In 1960 John Kennedy loses Mississippi. Carter would win there in '76, but lose in his 2nd presidential run. MS was the Democrats' first loss in the South due to the Civil Rights issue (sorry Oldiesfreak).
In 1964 Johnson wins DC against Goldwater, but loses Alabama and South Carolina. None of them have looked back since. The Civil Rights Act has played the main role in this, and Johnson's words about losing the South for a generation were obviously wrong, since it has been almost 50 years since that election. The Civil Rights Act is also the main reason DC and African-Americans have been so Democratic since. Goldwater's opposition to Civil Rights is still hurting the Republican brand among this group.
In 1968 Humphrey loses NC, IN, ND, SD, NE, KS, OK, MT, WY, ID, UT and AK. No Democrat has won these states since (some of them won them in their first run, but lost them in their second).
I'm not sure what the connection is, but it seems that Humphrey failed to connect with a lot of quiet, rural states, which I guess bought into Nixon's "law and order" and were not influenced much culturally by the counterculture movements of the '60s that changed politics in urban centers in later decades. Could that be what makes these states so hostile to the Democratic party to this day?
It had nothing to do with civil rights. It was because after WWII, a lot of people, and I mean a LOT, moved to the South from other parts of the country that were more pro-civil rights. And
the latest academic research shows that it was primarily economic issues, not race, that drove the shift.. Also, the religious conservatives' shift toward Republicans on abortion and gay marriage in the late 70s/early 80s had a lot to do with it too. And the "law and order" thing wasn't driven by Nixon, it was driven by Wallace. Nixon was a champion of civil rights throughout his life, especially as president. In 1960, the South wasn't as strong for Kennedy as for previous Democratic nominees because of anti-Catholicism, not racism. Finally, anti-Communism played a role, as well.
And for Democrats:
Kennedy: Mississippi
Carter carried Mississippi in 1976.
