In recently teaching about the development of the American suburbs, I was reminded of the description of “walking cities” in 1815 provided by historian Kenneth Jackson makes in Crabgrass Frontier:
The first important characteristic of the walking city was congestion. When Queen Victoria was born in 1819, London had about 800,000 residents and was the largest city on earth. Yet an individual could easily walk the three miles from Paddington, Kensington, Hammersmith, and Fulham, then on the very edges of the city, to the center in only two hours. In Liverpool, Birmingham, Manchester, and Glasgow, the area of new building was not even two miles from city hall. (14)
While the focus here is on congestion, the time it takes to walk through such density in a major city is notable: in a few hours, one could traverse a significant portion of the city.
Introduce technology with more speed – trains, streetcars, cars, etc. – and cities could expand in space. People could live further from work (the proximity of home to work for many is a feature of the 1815 city that Jackson also notes). The city could go on for miles. The suburbs could extend even further. But, the ability to see a significant portion of the city in a single walk became much harder.