Nice read, Musette. You might want to correct Wikipedia, which asserts that the "Shady Grove" tune "was traditionally used in Appalachia"   for "Little Musgrave/ Mattie Groves."

The Ballad Index mentions a text of "Shady Grove" from 1893. That would be the earliest I'm aware of.

The place name "Shady Grove" was once common in the U.S. There was one in Orange Co., N.Y., as early as 1760.

A Shady Grove post office was established in north Georgia in 1824, another in Gibson Co., Tennessee, by 1835, one in Russell Co., Alabama, by 1836, one in Buncombe Co., N.C., by 1838, and one in Jefferson Co., Tennessee, by 1854.

One Shady Grove in Kentucky is in Crittenden Co. in the state's far western corner. Another is near Paducah in the central part of the state. But there could have been others.

For some reason, the name of the N.C. Shady Grove was changed in 1838 to "Mud Creek."