This article records tradition as it has been passed down and reported. Its sources are not yet part of the atlas's verified catalogue.
After the Promontory Apartments established his working relationship with Ludwig Mies van der Rohe, Herbert Greenwald moved quickly to a far more ambitious commission: 860-880 Lake Shore Drive, announced in April 1949 with co-developer Robert Hall McCormick and financed by a 3.1 million dollar loan from Mutual Benefit Life Insurance Company secured that July. Groundbreaking came on December 17, 1949, with more than half the apartments already presold, a sign of how much confidence Greenwald's reputation, and Mies's growing one, already commanded before a single unit was finished. The design process was not without friction. Mies originally wanted fully open interiors throughout the towers, a purist expression of his architectural philosophy, but Greenwald insisted on adding interior walls between rooms, a genuinely practical demand from a developer who had to sell the units to actual residents. The dispute became serious enough that Mies reportedly came close to quitting the project entirely before the two men reached a compromise, a rare instance of a client pushing back hard enough on Mies's formal ideals to actually change the built outcome. Greenwald went on to develop a substantial run of further projects, the Algonquin Apartments from 1949 to 1951, 900-910 North Lake Shore Drive, also known as the Esplanade Apartments, from 1953 to 1956, Commonwealth Plaza across the same years, and Lafayette Park in Detroit, begun in 1955 and continued after his death through 1963, along with an unbuilt house designed for him personally in Lake Forest, Illinois. He died on February 3, 1959, in the crash of American Airlines Flight 320, a Lockheed L-188 Electra that came down in dense fog into New York's East River on approach to LaGuardia Airport, roughly 4,900 feet short of the runway. Sixty-five of the seventy-three people aboard were killed, in what was the first fatal crash of the Electra type, which had been in commercial service only about two weeks. Greenwald's body reportedly was never recovered, an abrupt and unresolved end for a developer whose partnership with Mies had, in barely a decade, produced some of the most consequential residential towers of postwar American architecture.