Final answer:
Hood's division, under the command of John Bell Hood following a recent leadership change, engaged Union forces at Peachtree Creek on July 20 but failed to achieve victory. His inability to concentrate forces, due to stretched Confederate defenses, resulted in a defeat allowing the Union to press on towards Atlanta.
Step-by-step explanation:
On July 2, during two hours of fighting, John Bell Hood's division faced significant challenges. After Hood replaced Johnston in response to President Davis's desire for a more aggressive approach, he found himself with no time to prepare his army. This led to an inadequate organization which contributed to Confederate failures.
During the battle at Peachtree Creek on July 20, Hood's attack was initially promising but ultimately unsuccessful due to the Union's strategic positioning and larger forces. Hood was unable to concentrate sufficient troops to win as Union forces stretched Confederate defenses thin.
Consequently, the Union repelled the Confederate attack and continued their advance towards Atlanta, which was heavily fortified but eventually had to be evacuated by Hood after suffering a defeat at Jonesborough and losing vital supply lines.