In the modern era, the Southern accent is receding in some places.
The dialects collectively known as Southern American English stretch across the south-eastern and south-central United States, but exclude the southernmost areas of Florida and the extreme western and south-western parts of Texas as well as the Rio Grande Valley (Laredo to Brownsville).
Features of the deeper interior Appalachian South largely became the basis for the newer Southern regional dialect; thus, older Southern American English primarily refers to the English spoken outside of Appalachia: the coastal and former plantation areas of the South, best documented before the Civil War, on the decline during the early 1900s, and basically non-existent in speakers born since the Civil Rights Movement.
Little unified these older Southern dialects, since they never formed a single homogeneous dialect region to begin with.
For English as spoken in South America, see South American English. largely superseding the older Southern American English dialects.
African-American English has many common points with Southern American English dialects due to the strong historical ties of African Americans to the South.The Southern United States underwent several major sound changes from the beginning to the middle of the twentieth century, during which a more unified, region-wide sound system developed, markedly different from the sound systems of the nineteenth-century Southern dialects.