In the decades following the American Revolution of the 1760s to 1780s, major population centers of the coastal American South, such as Norfolk, Virginia and Charleston, South Carolina maintained strong commercial and cultural ties to southern England and London. Thus, as the upper-class standard dialect around London changed, some of its features were mirrored by: the dialects of upper-class Americans in eastern Virginia and the Charleston area, followed by the regional dialects of these areas in general, regardless of socioeconomic class. One such example accent feature is the "r-dropping" (or non-rhoticity) of the late 18th and early 19th century, resulting in the similar r-dropping found in these American areas during the cultural "Old South". Contrarily, in Southern areas away from the major coasts and plantations (like Appalachia), and on certain isolated islands, accents mostly remained rhotic. Another example feature is the trap–bath split, which also helped define the eastern Virginia accent in its British-style imitation. The split was also adopted in the Gulf, Appalachian, and plantation regions of the South, though with their own unique articulation distinct from the British one. The feature is extinct in virtually all these areas today. By the time of the American Civil War in the 1860s, many different Southern accents had developed, namely: eastern Virginia accents (including the Tidewater accent), Lowcountry (or Charleston) accents, Appalachian accents, plantation accents (those primarily of the Black Belt region), and accents among secluded Pamlico and Chesapeake islands. Decline After the Civil War, the growth of timber, coal, railroad, steel, textile, and tobacco mill industries throughout the South, along with the whole country's resulting migration changes, likely contributed to the expansion of a more unified Southern accent (now associated with the 20th century), which gradually ousted 19th-century Southern accents. The South's 19th-century linguistic prestige was rooted in the plantation areas and higher-class White people, including features such as non-rhoticity. However, by the mid-20th century, linguistic features originating from Texas, Appalachian towns, and lower-class White people—such as rhoticity—were suddenly expanding throughout all the Southern States. Also, before World War II, the demographic tendency of the South was out-migration, but after the war a counter-tendency emerged, with the South receiving masses of migrant workers from the North, especially toward urban areas: another possible motivation for the abandonment of older Southern accent features. Finally, the Civil Rights Movement seems to have led White and Black Southerners alike to resist accent features associated