What happened at the battle of pines? ?

The Battle of Seven Pines was a battle in peninsular Virginia from May 31 to June 1, 1862. 
Although the Confederates were forced back toward Richmond, the battle halted the advance of the Union armies. Both sides suffered considerable casualties. 
Although more-or-less a draw, the battle was highly significant because the Confederate commander, Joseph E. Johnston, was badly wounded and had to be replaced. His replacement was Robert E. Lee, who would oversee the expulsion of the Union forces after the Seven Days Battle at the end of June 1862. 
Deemed "too cautious" in exploiting Union victories, McClellan was replaced despite a celebrated victory against Lee at Antietam in September 1862.

On May 31, Confederate General Joseph E. Johnston attempted to overwhelm two Federal corps that appeared isolated south of the Chickahominy River. The Confederate assaults, although not well coordinated, succeeded in driving back the IV Corps and inflicting heavy casualties. Reinforcements arrived, and both sides fed more and more troops into the action. Supported by the III Corps and Maj.