Valley Forge was a revolutionary war in the winter of 1777. There was a lack of materials: food, clothing, tents and more. It was extremely crowded and extremely cold. This led to disease to up to 10,000 people and the deaths of 2,000 people; mostly due to malnutrition, weather and some shooting from the British. The Americans ended up winning. They felt a sense of accomplishment and felt more disciplined after beating the British in Valley Forge. Nine days later, they fight again in the Battle of Monmouth and beat the British again.
I know that this summarization isn't that detailed - but I hope this helped you at least a little bit