If you haven't used this resource already, do so.
Across the Years in Prince George's County by Effie Gwynn Bowie
It has been through several printings. I just recently bought a two-volume set online, because the library here in Calvert County did not have any copies left.
Probably you will be able to locate it at a library in PG County.
There is quite a lot of info about the Digges family and Warburton Manor in the book. I just read where the families would send the slaves out on barges across the Potomac, meet the barges in the middle of the river, and board the folks for parties on the riversides. Can you image how dangerous that was, with the currents in the Potomac?

--Previous Message--
: I’m interested in learning more about Teresa
: Digges, daughter of William and sister of
: George and their brother Thomas Attwood
: Digges. I’ve been trying to develop a sense
: of the reaining family members at or around
: Warburton Manor from 1770-1790. Thomas was
: in London much of this period passing notes
: back and forth with news and British
: government proposals to John Adams and Ben
: Franklin in Paris. Thomas had written what
: in some quarters is thought the first novel
: by an American — and a pot-boiler it was;-)
: Thomas was accused of having embezzled funds
: by Franklin in matters relating to aid for
: prisoners of war in London jails, though the
: situation likely involved at least some
: misunderstanding. William, the father of
: these had died and left large debts. This
: was a confusing will which took decades to
: resolve. Teresa died near 1784 and I’ve not
: been able to find probate or cause. George
: died also before 1790 and left a huge mess
: and a pile of debts. After he’d returned to
: Warburton, and while hosting L’Enfant, then
: designing Washington DC, Thomas spend a good
: number of evenings across the river dining
: socially with George Washington and his wife
: toward the end of the latter’s life. If any
: one knows where I might source more
: information about the family during this
: period, I’d deeply appreciate the help.
: