>>1940871>moving onto the otherside of the reiver to use a ferry isn't really leaving the city.At the time, none of those were part of New York City, nor were any of them part of any continuous built-up urban area. Brooklyn crossed 100,000 population in the 1840s, Jersey City in the 1870s, Staten Island in the 1910s.
But if you consider those just natural outgrowths of urbanization and not cases of suburbanization, consider the streetcar suburbs, in particular the Huntington Real Estate empire knitted together by the Pacific Electric Railway. This rail system existed to drive development and settlement of developers' subdivision projects while still offering urban-type connectivity to the rest of the region. Another famous suburban development would be Hollywoodland; its famous sign originally erected to serve as an advertisement luring home-buyers to its hilly streets.
