The Cashua Street-Spring Street Historic District is a significant collection of intact residences constructed between ca. 1890 and ca. 1930. Many of the homes were owned by prominent Darlington citizens. The district contains thirty-nine contributing residential properties and twelve non-contributing properties. The residences along Cashua Street are large, two-story frame dwellings while the residences along Spring Street are smaller, one-story frame houses. Most of the residences have decorative woodwork and are significant examples of the builder’s art. Architectural styles include Victorian, Queen Anne, Colonial Revival, and Bungalow. The buildings are situated on large lots that are planted with trees and shrubs. Listed in the National Register February 10, 1988.