Philadelphia, commonly referred to as Philly, is the most populous city in the U.S. state of Pennsylvania. Philadelphia is the nation's sixth-most populous city, with a population of 1,603,797 in the 2020 census and is the urban core of the larger Delaware Valley, the nation's seventh-largest and one of the world's largest metropolitan regions consisting of 6.245 million residents in the metropolitan statistical area and 7.366 million residents in its combined statistical area. Philadelphia is known for its extensive contributions to United States history, especially the American Revolution, and served as the nation's capital until 1800. It maintains contemporary influence in business and industry, culture, sports, and music.

The American Revolution was a rebellion and political movement in the Thirteen Colonies which peaked when colonists initiated an ultimately successful war for independence against the Kingdom of Great Britain. Leaders of the American Revolution were colonial separatist leaders who originally sought more autonomy within the British political system as British subjects, but later assembled to support the Revolutionary War, which successfully ended British colonial rule over the colonies, establishing their independence, and leading to the creation of the United States of America.