The idea of the playground as a method for imbuing children with a sense of fair play and good manners originated in Germany where playgrounds were erected in connection to schools, although the first purpose built public-access playground was opened in a park in Manchester, England in 1859. Over time, organized playing areas have been adopted by other countries of the world and have become commonplace.
The first playground in the USA was built in San Francisco's Golden Gate Park in 1887. Recognizing the need for playgrounds, former President Theodore Roosevelt stated in 1907:City streets are unsatisfactory playgrounds for children because of the danger, because most good games are against the law, because they are too hot in summer, and because in crowded sections of the city they are apt to be schools of crime. Neither do small back yards nor ornamental grass plots meet the needs of any but the very small children. Older children who would play vigorous games must have places especially set aside for them; and, since play is a fundamental need, playgrounds should be provided for every child as much as schools. This means that they must be distributed over the cities in such a way as to be within walking distance of every boy and girl, as most children can not afford to pay carfare.
In post war London the landscape architect and children’s rights campaigner Lady Allen of Hurtwood introduced and popularised the concept of the ’junk playground’ - where the equipment was constructed from the recycled junk and rubble left over from the Blitz. She campaigned for facilities for children growing up in the new high-rise developments in Britain's cities and wrote a series of illustrated books on the subject of playgrounds, and at least one book on adventure playgrounds, spaces for free creativity by children, which helped the idea spread worldwide.
Source Wikipedia