Yes - there are numerous sources on this. Two good books on the subject are Southern Nation: Congress and White Supremacy After Reconstruction and The Unsolid South: Mass Politics and National Representation in a One-Party Enclave.

It would be hard to write this answer without going into the history of the United States since at least the 1850s, but here's a relatively brief recap.

The Democratic Party was the party in opposition to Republicans during the Reconstruction. The Compromise of 1877 resulted in Republicans winning the presidency, but the withdrawal and effective ending of the Reconstruction. This led to the entrenchment of the Democrats essentially having one party rule in the former confederacy and the implementation of Jim Crow laws to enforce White supremacy and deny Black voting rights and economic opportunity.

During the Progressive Era, Democrats and Republicans both pushed for some reforms of the political and legislative processes, and some Democrats in the north supported labor unions and union organizing, which was the beginnings of a factional split within the party.

Many bills passed by FDR (from the progressive wing of the party) required compromise with the southern Democrats, who wanted less protection for Black citizens in their states. For example, in the fight over creating the Social Security program, FDR was forced to exempt agricultural and domestic workers to get the bill passed. Many of the workers in these economic sectors in the South were Black. This provision excluded about 65% of Black workers from participation in Social Security.

After the assassinations of President Kennedy and Martin Luther King, Jr., President Johnson worked to pass the Civil Rights act over objections from southern Democrats in his party. When he signed the bill, he famously declared that it would lead to the death of his party in the South for a generation. Over the next several decades, southern Democrats left the party to join the opposition - the Republicans. Even some politicians that have been recently active in national news switched parties. For example, Rick Perry, the former Republican Governor of Texas and Presidential candidate, switched from Democrat to Republican in the 80s. The elections of Nixon and Reagan saw the south push into the Republican camp electorally.