Which union general was so slow to attack lee's men?

The Union general known for being slow to attack Robert E. Lee's men was General George B. McClellan. McClellan's cautious approach and reluctance to engage Lee's forces decisively during the Peninsula Campaign and at Antietam frustrated President Lincoln and many in the Union military. His hesitance was often attributed to an overestimation of the Confederate forces and a desire to avoid unnecessary casualties. Ultimately, this delay contributed to missed opportunities in the Civil War.