I do not know much about the Daltons of Pittsylvania County but tracing land ownership in a locality can be enlightening.
The Archives of Virginia (located in The Library of Virginia, Richmond, in the Archives Dept.) shows that in 1732 a Timothy Dalton received a land grant in Hanover County, VA, followed by Timothy Dalton, Jr., receiving 2 grants in 1738. Then in 1742 Samuel Dalton received a land grant in Louisa County (Louisa County was created out of the territory of Hanover county in 1742).
Then in 1759 a Timothy Dalton received a grant for 150 acres
on Frying Pan Creek in Halifax County plus a second grant for 1,180 acres of land on Pigg River in Halifax County.
Pittsylvania County was created out of Halifax County in 1767 and at that time those land grant sites fell into Pittsylvania County. In other worlds a Timothy Dalton had
1,330 acres of land in the Northwest section of the new Pittsylvania County.
The next land grants to a Dalton in Pittsylvania are a small number of acres to Thomas Dalton of Pittsylvania County in 1801 and to William Dalton in Pittsylvania County in 1802.
Are you saying the Daltons you named are the descendants of this Timothy Dalton?
By the way, James L. Dalton is the son of William Dalton married Sarah Mayhew and William was son of Samuel married Catherine Pickeral, both of whom were born in 1805 in Pittsylvania County. (I usually do find the links but it can take some time.)