seldom seen richard nickel images of gene summers-designed mccormick center under construction

when richard nickel meticulously documented the construction of mccormick place in the summer of 1969, he only printed a limited number of large photographs that would i periodically see in various collections and exhibits.
when i ran across one this past week, i decided to dig a little deeper into his archive, where i found several long-forgotten contact sheets filled with riveting images chronicling early stages of construction (see below).

as i carefully studied and digitized the images, i grew increasingly interested in the building, its structural components (e.g., cross-shaped columns used to support the space frame) and how they were pieced together.
now i'm utterly obsessed with this building and the technology used to build it, reading anything and everything, with no end in sight.
mccormick was designed by gene summers of c.f. murphy & associates. completed in 1970.

images courtesy of ryerson and burnham, art institute of chicago.