If you were plotting a Frank Lloyd Wright tour of American architecture, the 2700 block of West Burnham Street in Milwaukee might not make your itinerary. But on this quiet street, you can find evidence of the architect’s career-long obsession with creating affordable, sometimes prefabricated, housing for the masses.

Crafted between 1915 and 1917 with precut factory lumber to save cash and labor, a half-dozen duplexes and bungalows on this block—the American System-Built Homes, as they have come to be known—were Wright’s first attempts at attainable architecture. He did more sketches for this project than any other in his career, according to Dale Gyure, a Wright scholar. Gyure notes that the homes embody ideas from “The Art and Craft of the Machine,” a 1901 speech in which Wright spoke of building affordable housing by letting machines free humans for more high-level design.

Wright was cooking up an ambitious plan with a developer, Arthur L. Richards, to sell homes via a car-dealership model when the combination of a sluggish economy and the entry of the United States into World War I effectively scuttled the project, according to Sidney K. Robinson, a professor emeritus of modern architecture at the University of Illinois at Chicago.

Wright revisited the affordable home concept often. His Usonian homes, which were built starting in the late 1930s, represent a more ambitious attempt at a design system that could be replicated, with concrete slabs embedded with piping for radiant heating and carports instead of garages. Writing in Architectural Forum in 1938, Wright identified the challenge of building “the house of moderate cost” as “not only America’s major architectural problem, but the problem most difficult to her major architects. I would rather solve it with satisfaction to myself than anything I can think of.”

These projects led to the Erdman homes, a series of three prefabricated structures that Wright designed for Marshall Erdman, a builder who had collaborated with Wright on the Unitarian Meeting House in Madison, Wisconsin. Each “set” would come with all the major pieces needed to assemble a home; the buyer would have to provide the foundation, wiring, and plumbing, and even submit a topographic map for Wright’s approval. The layouts of the two models that were constructed—the L-shaped No. 1 and flat-roofed No. 2—would “immediately catch your eye,” Gyure says, as looking a bit like previous Usonian models, more evidence of Wright’s continual refinement of affordable housing concepts.

“Wright wasn’t trying to change the manufacturing or prefab system” with these experiments, Gyure says. “He was trying to take advantage of it.”

Read more about Frank Lloyd Wright's prefab legacy, epitomized by a light-on-the-land structure owned by his grandson Tim Wright, on a plot of land in Wisconsin near the architect's famed estate Taliesin.