The two battles that had significant impacts on Confederate supply lines are:
B. The Battle of Atlanta significantly affected Confederate supply lines because Union forces destroyed a major transportation and railway hub in the South. This battle was crucial for disrupting the South's transportation network and supply routes, making it difficult for Confederate forces to move troops and supplies.
D. The Battle of Vicksburg significantly affected Confederate supply lines because Union forces took control of an important strategic location on the Mississippi River. Vicksburg was a key stronghold for the Confederacy along the Mississippi River, and its capture by Union forces effectively split the Confederacy in two and disrupted their ability to transport supplies and reinforcements across the river.
Together, these battles severely hindered the Confederacy's logistical capabilities, contributing to their eventual defeat in the Civil War.