Nelson Family of Maryland

My Nelson family line also goes back to the southeast Chesapeake Bay area, possibly colonial Maryland (Worcester and/or Somerset Co) to the early and mid 1700's. My ancestral line came south in late 1700's via Georgia. Some given names are John, William and Thomas. My second great grandfather, Thomas Nelson was b. in 1802 in MD and married in GA. I believe his father may have been named William b. in MD c. 1780-85. Some in-law surnames may have been Covington, Mezick/Messick and Kemp. Does any of this sound familiar?