For the 1939 World’s Fair, city agencies were invited to produce exhibits for the New York City Pavilion. The Department of Water Supply, Gas and Electricity (a New York City Department of Environmental Protection predecessor agency) commissioned the Cartographic Survey Force of the Works Progress Administration to create the large "Relief Map of the New York City Water Supply System" and watershed. Work began in 1938, and a team of map builders toiled over the map with an immense depression-era budget of $100,000 (). At , the map was too big for the allocated space in the city pavilion, resulting in its elimination from the World’s Fair. Ten years later, the map made its first and only public appearance at the city’s Golden Anniversary Exposition in Manhattan’s Grand Central Palace.