Several park advocacy groups were formed in the early 20th century. To preserve the park's character, the citywide Parks and Playground Association, and a consortium of multiple Central Park civic groups operating under the Parks Conservation Association, were formed in the 1900s and 1910s.[160] These associations advocated against such changes to the park as the construction of a library,[161] sports stadium,[162] a cultural center,[163] and an underground parking lot.[164] A third group, the Central Park Association, was created in 1926.[160] The Central Park Association and the Parks and Playgrounds Association were merged into the Park Association of New York City two years later.[165]