A collection of historical and genalogical records
If I read your own page correctly, you are looking for William Douglass, b1720 in Charles Co. MD.USA,D-1786, Franklin Co.PA.,USA? Forgive me, but I have no idea where MD is! I can guess the other initials, but I do not know that one.
Also from your own page, I think he married Rachael, and had children Children: Robert, Samuel, William, Martha, Joseph (your 4-G), Rachael and Mary. Do you have any dates for these people?
Again, from your page, I think this Joseph married Rebecah Robb b-1/28/1795 KY,USA d-2/17/1887,KY and his son, Robert (your 3-G) married Sarah Robb-b-1805, KY d-c.1863, Logansport,IND. You want to know if the two Robbs are related.
PS Oh! I have just re-read your title, and I now know MD is Maryland! My point is, really, that for those of us outside the US of A, abbreviations of states and counties do not come readily to us. It is good if we can have them in full.
OK - according to Ancestry.com -- William Douglass father was Thomas DOUGLAS --Birth 1692 in Picawaxon, Charles, Maryland, United States -- Death 11 Feb 1756 in Picawaxon, Charles, Maryland, United States. His wife appears to be Elizabeth Gardner (Gardiner?) --Birth 1696 in Charles, Maryland, United States-Death 29 Aug 1758 in Charles, Maryland, United States. and it goes way back from there if these links are correct.