From December 19, 1777 to June 19, 1778, the main body of the Continental Army (approximately 12,000 troops) was encamped at Valley Forge. The site was chosen because it was between the seat of the Second Continental Congress in York, supply depots in Reading, and British forces in Philadelphia away, which fell after the Battle of Brandywine, in which many American soldiers were injured, including the Marquis de Lafayette This was a time of great suffering for the army, but it was also a time of retraining and rejuvenation. The shared hardship of the officers and soldiers of the army, combined with Baron Friedrich von Steuben's professional military training program, are considered key to the subsequent success of the Continental Army and marks a turning point in the Revolutionary War.