Which Springfield, Illinois house did Wright design for Susan Lawrence Dana?

The Springfield, Illinois house Frank Lloyd Wright designed for Susan Lawrence Dana was the Dana-Thomas House.

Built between 1902 and 1904 at 301 East Lawrence Avenue, the residence was commissioned by Susan Lawrence Dana, a wealthy philanthropist and heiress. Rather than simply adding rooms to her existing Italianate mansion, Dana engaged Wright to transform the property into an expansive Prairie School home reflecting her artistic interests and independent personality.

The house contains 35 rooms arranged across 16 different levels, with a long west wing, broad horizontal lines, art glass, and carefully coordinated interiors. Wright designed more than 100 pieces of white-oak furniture for the building, as well as decorative elements suited to Dana's collection of Japanese prints. A gallery supported musical entertaining, while the library included special display easels.

Dana lived there from 1904 until roughly 1928, later moving to a smaller house as finances and health declined. The property is sometimes confused with Wright's Willits or Winslow houses, but the name Dana-Thomas specifically identifies his Springfield commission for Susan Lawrence Dana.