Final answer:
General Von Steuben had a significant impact on the Battle of Monmouth by transforming Washington's troops into a professional fighting force through his training methods.
Step-by-step explanation:
General Von Steuben had a significant impact on the Battle of Monmouth during the American Revolutionary War. He arrived in February 1778 and implemented a thorough training course for Washington's troops, transforming them into a professional fighting force. By drilling a small corps of soldiers and having them train others, he improved the army's discipline and effectiveness. Von Steuben's experience and drill manual, Regulations for the Order and Discipline of the Troops of the United States, influenced military practices in the United States for decades to come.