Here are some links to websites that might be helpful.
Surname Resource Pages at RootsWeb.com
WHITFILL
FOWLER
MATTINGLY
LANGLEY
CLARK
CLARKE
COLLARD
DURBIN
WHITFILL
Descendents of Joseph Whitfill and Elizabeth Riggs - a searchable database on RootsWeb's WorldConnect Project
Whitfill Message Board - on FamilyHistory.com
WHITFIELD
The Whitfields of Kentucky and Indiana - Joe Whitfield's FTM site about the descendants of Barney Whitfield
MATTINGLY
Pat Place’s GenWeb Page -a Mattingly database
Mattingly Family - a UK based website
LANGLEY
Langley Family of Southern Maryland
Langley Family Genealogy Database
CLARK
Jerry Clark's website, including Maryland Clarks