I was told that my great grandfather was named George Washington Thrapp. My grandfather was Bert Thrapp, married to Catherine Marie Thrapp nee Miller. My mother who died fairly recently was Lucille Agness Thrapp.
If we're talking the same line here, I may have a little information that could help.
I have just started doing geneaology. I'd have to check to see if there is Davidson information, because I don't know. My information is mainly from George Washington Thrapp to Bert Thrapp and his offspring.
Catherine Vanicek