Fort McHenry’s earthworks have long faced a daily assault from rain, snow, freezing, and thawing that can kill grass, expose soil, and allow erosion to spread until parts of the original fort wash away. Throughout the fort’s history, the military sought ways to keep these earthen defenses intact by preventing livestock and people from climbing the mounds. After the site became a unit of the National Park Service in 1933, the government balanced greater public access with preservation of the historic earthworks. Under President Franklin Delano Roosevelt’s New Deal, amid the mass unemployment of the Great Depression, laborers from the Works Progress Administration restored much of the old fort, and in August 1938 they laid thousands of feet of brick pathways that remain in use.