The district's importance had waned with the western movement of City Hall and other institutions, but it remained an active and occupied business center. The first proposal for an Independence Hall park originated in 1915, when architects Albert Kelsey and D. Knickerbacker Boyd proposed clearing the half-block between Chestnut Street and Ludlow Street in front of Independence Hall. Kelsey and Boyd were motivated by a desire to create a fitting setting for Independence Hall, lessen the fire hazard, reduce congestion, and beautify the entire district. The idea for a park gained momentum in the 1920s and 1930s, with patriotic sentiment accompanying the American Sesqui-Centennial in 1926. The commencement of World War II led to a heightened sense of patriotism and urgency toward the protection of national monuments.