Keywords: City planning Social aspects 19th century ; History ; City planning Social aspects 20th century ; History ; Urban ecology (Sociology) History 19th century ; Urban ecology (Sociology) History 20th century ; City and town life Psychological aspects 19th century ; History ; City and town life Psychological aspects 20th century ; History ; Public spaces Social aspects 19th century ; History ; Public spaces Social aspects 20th century ; History ; City planning ; City planning ; Urban ecology (Sociology) ; Urban ecology (Sociology) ; City and town life ; City and town life ; Public spaces ; Public spaces ; USA ; Stadt ; Verstädterung ; Interaktion ; Geschichte