The James River is a river in Virginia that begins in the Appalachian Mountains and flows from the confluence of the Cowpasture and Jackson Rivers in Botetourt County 348 miles to the Chesapeake Bay. The river length extends to 444 miles if the Jackson River, the longer of its two headwaters, is included. It is the longest river in Virginia. Jamestown …The James River is a river in Virginia that begins in the Appalachian Mountains and flows from the confluence of the Cowpasture and Jackson Rivers in Botetourt County 348 miles to the Chesapeake Bay. The river length extends to 444 miles if the Jackson River, the longer of its two headwaters, is included. It is the longest river in Virginia. Jamestown and Williamsburg, Virginia's first colonial capitals, and Richmond, Virginia's current capital, lie on the James River.