In the early twentieth century, as recreation became a widespread pursuit and the Chesapeake Bay shoreline filled with swimming beaches, waterfront amusement parks, and summer communities, the Olmstead Brothers included Ft Smallwood in their Baltimore City Park Plan. In July 1927, the City of Baltimore acquired the former military installation for use as a public beach and park, and Ft Smallwood Park opened in 1929 with public beaches and recreation space. Growing prosperity in the Roaring Twenties gave residents of Baltimore City, rural farms, and villages the means and leisure time to travel by train, steamship, and increasingly by automobile in search of rest, relaxation, and fresh air. The park reached peak popularity during the 1940s following World War II. In the 1950s, the NAACP challenged Ft Smallwood's policies of racial segregation in Federal Court in a case argued and won by future Supreme Court Justice Thurgood Marshall. Attendance then declined sharply, and the park fell into disrepair until 2006, when Anne Arundel County incorporated Ft Smallwood into its County Park System.