Mannassass Junction. Pope, seeing this as an opportunity to get rid of Jackson, rapidly got his disjointed Corps together during the night of August 28–29 through a series of forced marches, and then hurriedly threw them piecemeal at Jackson in an attempt to break his line. Because of this, Pope was unable to get more than 32,000 men into action against Jackson's 22,000. Even though Union troops broke Confederate lines at points, the Confederates hung on tenaciously and quickly filled the gaps. The 20th Indiana was rushed into the action on the evening of the 27th and arrived early in the morning of the 28th. On the 29th, the Regiment was maneuvered into position opposite an unfinished railroad which served as a sort of breastwork for the Confederate forces. After forming a skirmish line, the regiment advanced roughly two miles to drive the confederates out of their positions. The regiment suffered the majority of their losses in this action, but were successful in temporarily breaking the Confederate line. By 4:00 P.M., the regiment had crossed the railroad and had slowed their advance. While the 20th Indiana had been advancing, the rest of the army had come under significant pressure from Confederate forces, breaking parts of the Union lines. This prompted General Phillip Kearny to order the 20th Indiana to wheel left in order to prevent a potential flank attack. Moving into position, the regiment took cover among the high grass and brush provided by the immediate area. This maneuver prevented the regiment from being attacked head-on by a group of Confederate soldiers. As the Confederates passed by the regiment, Private Peter Schwartz of Company I suddenly stood up and opened fire on the Confederates. The regiment quickly followed Schwartz's example, completely destroying the extreme left wing of the Confederate advance. Shortly after this success, during a withdrawal ordered by General Kearny, Col William Brown was shot through the temple by a Confederate sharpshooter. Maj. Wheeler assumed command of the regiment. The regiment spent the night of August 29–30 in the field near the railroad. In the morning they were relieved and relegated to minor support roles during the rest of the battle. Battle of Fredericksburg Although General McClellan had routed General Lee's army at the Battle of Antietam, he did not attempt to pursue or destroy it. This irritated President Abraham Lincoln, who was looking to destroy the Confederacy quickly,