Because so much of the military activity in the region was focused along the rivers, the shifting courses of the Mississippi and Ohio rivers and the flooding of the Tennessee as a result of the completion of Kentucky Dam in 1944 have severely eroded or flooded many, if not, most, of the potential historical resources of the region from the Civil War era.
(so much of the military activity in the region; was focused; along the rivers) (the shifting courses of the Mississippi and Ohio rivers and the flooding of the Tennessee as a result of the completion of Kentucky Dam in 1944; have severely eroded; )
so much of the military activity in the region the shifting courses of the Mississippi and Ohio rivers and the flooding of the Tennessee as a result of the completion of Kentucky Dam in 1944
was focused have severely eroded
along the rivers