I am a descendant of Thomas Marion Harp and Sarah Tudor. If anyone has any information on either of these two families please contact me via email at firstname.lastname@example.org.
If you have these people in your tree and have enable Smart Matching (if that is available to you) then you would receive notification of any matches.
I also suggest using http://www.genesreunited.com/relations/search/. That will tell you who has matches on their site.