How did the lack of training for new recruits hurt the Union efforts at the Battle of Antietam in 1862?

Answer 1

The US Civil War required that proper training and drilling exercises were vital to success on the battlefield. A perfect example of this was when a number of Union regiments were raised in the Summer of 1862. Often times new recruits were placed on battlefields before they were ready. During the Battle of Antietam, the Union's Twelve Corps received three new Pennsylvania regiments, this amounted to one half of a brigade. When these troops were ordered to maneuver from a column formation into a line formation within 70 yards of Rebel forces, the troops could not do it. This was a five week-old regiment that had received no training in this maneuver. The groups colonel was shot immediately after giving the order and in a few minutes the collapsed. They were taken out of the battle because of poor training.