Mapping Virginia

Nearly half a century after John Smith first landed in Jamestown, the British continued to hold a major misunderstanding about the geography of North America. Examine the map below to see if you can figure out their mistake.

The map reads, ''Sir Francis Drake was on this sea and landed Ano 1577 in 37 deg. Where he tooke Possession in the name of Q: Eliza: Calling it new Albion. Whole happy shores, (in ten days march with 50 foote and 30 horsemen from the head of the James River, over those hills and through the rich adjacent Vallyes beautified with as profitable rivers, which necessarily must run into ye peacefull Indian Sea,) may be discovered to the exceeding benefit of Great Brittain, and joye of all true English.''

^{Source: Williams, Edward. A mapp of Virginia discouered to ye Falls, and in it's Latt: From 35 deg: & 1/2 neer Florida to 41 deg: bounds of new England. 1651. John Carter Brown Library, Brown University.}