18th or 19th century, American cities. Also how did the mode of commute differ with regard to status. Now the poor seem to live in the cities and the well-off live in the suburbs, was that the case back then?
Prior to the rise of the automobile, most people would have gotten to work by walking or on a streetcar and lived near to their work.
The idea of wealthy people living in the suburbs and the poor in the inner-city is a largely an American invention. Though there was some early suburbanization, it really kicked off after World War II. Soldiers returning from WWII received VA-back mortgages on good terms, and so there was a huge surge in the demand for modest single-family housing. As part of the terms of the mortgages though, the VA often prohibited people from buying homes within inner-cities.
Why? The suburbs were often "whites only" in practice and African-Americans stuck in the inner-city didn't have the same access to capital from the banks so the housing stock deteriorated. Because of this, lenders like the VA "redlined" the inner-cities (not wanting to give mortgages for homes in areas with plummeting property values), preventing capital from being spent in the inner-city, creating a negative feedback loop. People with money who lived in the inner-cities got out to avoid the falling property values, making the problem even worse.
It's only been in the past couple decades that we've really seen the growth of housing in downtowns again outside of very large cities so I'll hold off on that to avoid the 20 year rule.
Here's an article about the development of Chicago and public transportation: http://www.encyclopedia.chicagohistory.org/pages/323.html
In the olden days most people lived in rural areas. Suburbs didn't really exist until railroads were built.