Last night I posted my recent finds to a number of detecting forums that I frequent. I highly recommend posting your finds on such websites, because the large user base can provide an incredible wealth of crowdsourced historical information on just about any topic. As it would happen, I received an alternate ID for the maker's mark on my silver spoon, and after some more digging (hehe) I believe this to be more accurate.
I'm now confident that the spoon was crafted by Henry White of Fredericksburg, Virginia sometime before 1827. So it's not a colonial relic, but an artifact of the early American south. The next goal would be to definitively connect the monogram to the family who I believe the spoon belonged to. It's a long shot, but the research will be fun anyways. Another avenue of research would be to specifically ID the unit camped where the spoon was found - but I think that will require more literal digging. Looks like I've got some work to do!