John Deere World Headquarters: Steel That Weathers Into the Prairie

When John Deere's chairman William Hewitt decided in the mid-nineteen fifties that the company needed a new headquarters, he faced pressure to move it east or west, toward one of the major financial capitals. He refused. The company had grown from the Illinois prairie, and it would stay rooted there. What he built instead became one of the most celebrated pieces of corporate architecture in the United States.

Hewitt commissioned Eero Saarinen, the Finnish-American architect then at the height of his powers, designing simultaneously the Gateway Arch in Saint Louis, Dulles International Airport outside Washington, and the TWA Terminal in New York. The Moline commission was Saarinen's last major corporate project. He died in nineteen sixty-one, three years before the building opened, and his partner Kevin Roche completed the work.

The defining choice was the material: Cor-Ten steel, a weathering alloy that had previously been used for railroad freight cars and military tanks, never for a landmark building. Cor-Ten does not corrode the way conventional steel does. Instead it forms a dense, stable layer of rust-colored oxide that seals the surface against further degradation, and it deepens in color with each passing season. Saarinen described this as a nature-culture hybrid: a material that would change slowly over time, aging into its landscape the way a barn does, echoing the warm bark of the surrounding oaks.

Construction required just over two thousand tons of Cor-Ten steel, fourteen thousand six hundred cubic yards of concrete, and nearly five hundred sixty-two thousand face bricks. The campus sits on rolling terrain whose hills Saarinen carefully preserved during construction, integrating the building into the land rather than leveling it for a flat foundation.

The building opened in nineteen sixty-four and was immediately recognized as a landmark of American modernism. It helped establish Cor-Ten steel as an architectural material, later used by Richard Serra, Renzo Piano, and dozens of other architects worldwide. Driving past Moline today, you can see it from the highway: a warm rust-orange structure settled into the green Midwestern hills, looking less like a corporate headquarters and more like something the landscape itself decided to grow.