SAVANNAH, Ga.—Unlike the 20th-century experiment that reinvented much of America’s built environment as suburban sprawl, colonial-era experiments in city design have proven to be both highly adaptable and enduringly beautiful.

Thus it is no accident that leading urbanists have flocked this week to Savannah, Georgia, for the annual Congress for the New Urbanism, to collaborate on how to recover a tradition of human-scale cities that may have once seemed a quaint province of historic preservationists.

Of course, Savannah is indeed quaint, and preservation efforts have made walking down its intact antebellum streets somewhat like going back in time. Shaded by live oaks and Spanish moss, the city’s famous series of public squares break up the street grid every few blocks and are perhaps its signature feature. Remarkably, these public spaces were there from the beginning, when the first sections of the city were laid out in the 1730s.

The Englishman James Oglethorpe, a leading innovator of his day who was in conversation with leading lights such as philosopher George Berkeley and American founder John Adams, is today celebrated for coming up with the unique grid-and-square system, which allowed the city to expand over subsequent decades—and in fact, centuries—while maintaining both a rational and beautiful urban-design framework.

It was a plan that drew on Enlightenment-era confidence in reason, though it was not an entirely secular one: The series of squares allowed for multiple church buildings, for example, to sit in prominent locations. (Catholics were initially excluded from the new colony, but one of America’s oldest Jewish congregations was formed in Savannah in 1735.) This pluralistic approach was in contrast to many of the settlements in New England, where there was little toleration of those outside the reigning Congregationalist regime.

The physical form of Oglethorpe’s plan was made up largely of 60-foot-wide lots, grouped into “tithings” of ten, and allowed for a wide variety of uses, from large single-family detached homes to sets of three slim rowhouses. All these residential rows were backed by “lanes,” the Savannah parlance for an alley, which Savannah College of Art and Design Professor Robin Williams explained have through centuries of technological change provided a utilitarian space for hiding infrastructure—stables, sewers, electric and telephone poles. (And against the original vision of founder Oglethorpe, they also were long a corridor where slaves were hidden from the front of the community.) Closer to the squares and in between residential sections are “trust” lots, or places dedicated to civic or public uses.

Notre Dame School of Architecture Professor Philip Bess argued at one Savannah CNU session that the city’s design has many virtues, but is not perfect. The wards, the groupings of small lots around squares that measure only 600 feet square and a bit over 10 acres, “are arguably too small,“ with the result that open space may actually appear too often as one moves through the urban fabric. Still, Bess laments that Savannah “never become a model” for American cities, “but it should have.” He pointed out that Chicago’s grid, for example, lacks any system of public neighborhood spaces, and suffers for it when it comes to the placement of prominent civic and religious buildings.

Bess’ Notre Dame graduate students have thus embarked on a project to design a new railroad suburb for Chicago inspired by Savannah. The new model takes the advantages of the Savannah approach—easily replicable mixed-use neighborhoods that plug in to the existing order, allowing for straightforward and incremental city expansion over time—while correcting for what Bess sees as the minor deficiencies of design monotony and somewhat of an imbalance between public and private realms.

An attempt to recreate all the charm and livability of a place like Savannah overnight would be futile, but many New Urbanists believe that the basic DNA created by Oglethorpe and others holds lessons for those who seek to create communities that are both sustainable and beautiful. The emphasis on high-quality public spaces that make moderate density livable, for example, is a lesson that can be applied to any number of new and existing neighborhoods.

There is increasing demand for the kind of traditional urbanism seen in Savannah in real estate markets—with the result that unless the market and regulatory authorities create more Savannahs, only the most wealthy among us will be able to live in such places.

This wasn’t always the case. Savannah’s economic success over the last few decades has led to a new problem of balancing increasing tourism with the needs of existing residents. To remind the Congress how much things have changed, local activist Vaughnette Goode Walker read a passage from the March 1990 issue of The Atlantic, in which a travel writer reported that “Savannah doesn’t know how good it is. That’s why it’s so fun to visit.”

Today Savannah knows how good it is. New Urbanists know, too. And increasing numbers of Americans want to live in a place inspired by its simple but captivating design.

Lewis McCrary is executive editor of The American Conservative.