Independence National Historical Park preserves historical structures associated with the American Revolution and the founding and growth of the United States. Independence Hall, the stately building with the bell tower and clock across the lawn, stands in a revitalized landscape designed to preserve the place where the Declaration of Independence and U.S. Constitution were debated, adopted, and signed. As the city and nation grew, the area surrounding Independence Hall filled with densely packed houses and businesses. In the early 1900s, local civic leaders led by Judge Edwin O. Lewis advocated protecting Independence Hall and other historic buildings for future generations as part of an effort to revitalize the area. The U.S. Congress established Independence National Historical Park in 1948 as a unit of the National Park Service. Here, the National Park Service pioneered new methods of historic preservation and established standards for historic building restoration, while the surrounding green space was designed to protect Independence Hall and nearby historic buildings and also provide a place for people to gather.