From Fred:

(this pertains to the 2nd map below)

"...I requested the Henry map and the librarian brings out a 5' by 5' folio and not a copy.
This is one of the original size, so you can zoom in and still retain detail. Note Wathall
just above the James and Appomattox rivers split--above Bermuda."
 

Just for reference, the James River at Jamestown is one to two miles wide.