Where is Louis Kahn at Greenbelt Knoll?

A carefully worded historical marker stands at the corner of Holme Avenue and Longford Street in Northeast Philly, designating the entrance to Greenbelt Knoll, a collection of 18 midcentury modern houses tucked inside a wooded park on a cul-de-sac. The development, completed in 1956, was the first racially integrated suburban development planned in the city and among the first in the country.

Its architectural pedigree matches its socio-cultural significance. “Prominent building and landscape architects, including Robert Bishop, Margaret Duncan, and Louis Kahn, created Modernist houses in the natural setting of Pennypack Park,” the marker reads.

The name of Philly’s own Louis Kahn, a celebrated 20th-century architect, may immediately jump out at modernist aficionados reading the sign. Other mentions of the Greenbelt Knoll project, including its successful nomination forms to the Philadelphia and national registers of historic places, have been less cautiously worded. These go so far as to claim that Louis Kahn consulted Montgomery & Bishop (the project’s lead architectural firm) on Greenbelt Knoll specifically, not just for developments in the Pennypack Park area. Kahn has been endlessly name-dropped in articles, blog posts, and books about Greenbelt Knoll.

You won’t find the project in the index of a Kahn book, though. It isn’t included in his recently published biography, You Say to Brick: The Life of Louis Kahn, and the archival paper trail comes up short, too. There is no mention of Kahn’s involvement in the files of Montgomery & Bishop. Nor is there a Louis Kahn file in the papers of Morris Milgram, the socially minded developer who conceived the project and ended up living there himself at No. 5 Longford Street.

So how did this architectural urban legend come about? “It’s something of a mystery,” says William Whitaker, the curator and collections manager of the architectural archives at the University of Pennsylvania (where Kahn was a faculty member) and co-author of The Houses of Louis Kahn.

The rumor’s source is largely attributed to a single black-and-white photograph, taken at an unknown date and in an unknown location. The photograph depicts six men, including Kahn, architects Newcomb Montgomery and Robert Bishop, developers George Otto and Morris Milgram, and contractor William Jones. The group crowds around a rendering drawn by Kahn, who holds a pencil in his hand as proof of his authorship, bearing the inscription: “This is wishing a marvelous success. Louis I. Kahn.”

A cropped version of Kahn’s drawing was used on the Greenbelt Knoll sales brochure, but his name doesn’t appear on any of the material (not even under the drawing).

And that’s the long and short of it.

According to Whitaker, the extent of Kahn’s involvement was in promoting the project. Though he had already designed the Yale University Gallery of Art, there wasn’t a lot of buzz around Kahn’s career during that time. He did, however, have a few local public housing projects under his belt already, including one across the street from Greenbelt Knoll called Pennypack Woods, which was commissioned by the Federal Public Housing Authority during World War II.

Other early housing projects include the New Deal town of Jersey Homesteads in New Jersey, and the now-demolished Mill Creek Apartments in West Philly. He had also collaborated on Carver Court, a cluster of 100 housing units earmarked for African-American steelworkers outside Coatesville, Pennsylvania, that was included in an exhibition in New York’s Museum of Modern Art, Built in the USA, in 1944.

As for what would personally motivate Kahn to market a project by another firm, it likely had something to do with the radical concept of who’d be living in the houses. The unprecedented project was committed to a ratio of 55 percent white owners and 45 percent nonwhite owners, before the height of the civil rights movement.

“It’s not that he needed the money,” Whitaker says. “Maybe it’s something that you believe in, and that you want to be connected to and help advance. I think [Kahn’s involvement] was limited in terms of time to a few weeks or a week, and that it related to marketing. There had to be a reason why Milgram felt like he needed to reach out to someone like Kahn and ask for the participation.”

With our 21st-century hindsight, it seems like a no-brainer to link the now-illustrious Kahn with this (or any other) project. But how and why Kahn was involved in Greenbelt Knoll remains a mystery, glossed over by ambiguous text on a marker that wants to give Kahn credit without spelling it out.