In 1958, Fortune magazine published the first major essay by Jane Jacobs that laid out her case against modernist urban developers. Downtown is for People was the catalyst for the publication of Jacobs’ seminal The Death and Life of Great American Cities three years later.

You’ve got to get out and walk. Walk, and you will see that many of the assumptions on which the projects depend are visibly wrong. You will see, for example; that a worthy and well-kept institutional center does not necessarily upgrade its surroundings. (Look at the blight-engulfed urban universities, or the petered-out environs of such ambitious landmarks as the civic auditorium in St. Louis and the downtown mall in Cleveland.) You will see that suburban amenity is not what people seek downtown. (Look at Pittsburghers by the thousands climbing forty-two steps to enter the very urban Mellon Square, but balking at crossing the street into the ersatz suburb of Gateway Center.)

You will see that it is not the nature of downtown to decentralize. Notice how astonishingly small a place it is; how abruptly it gives way, outside the small, high-powered core, to underused area. Its tendency is not to fly apart but to become denser, more compact. Nor is this tendency some leftover from the past; the number of people working within the cores has been on the increase, and given the long-term growth in white-collar work it will continue so. The tendency to become denser is a fundamental quality of downtown and it persists for good and sensible reasons.

If you get out and walk, you see all sorts of other clues. Why is the hub of downtown such a mixture of things? Why do office workers on New York’s handsome Park Avenue turn off to Lexington or Madison Avenue at the first corner they reach? Why is a good steak house usually in an old building? Why are short blocks apt to be busier than long ones?

It is the premise of this article that the best way to plan for downtown is to see how people use it today; to look for its strengths and to exploit and reinforce them. There is no logic that can be superimposed on the city; people make it, and it is to them, not buildings, that we must fit our plans. This does not mean accepting the present; downtown does need an overhaul, it is dirty, it is congested. But there are things that are right about it too, and by simple old-fashioned observation we can see what they are. We can see what people like.