Nestled in the heart of Clayton is the city's oldest residence: Hanley House at 7600 Westmoreland Ave. This Greek Revival-style farmhouse was built in 1855, and is listed on the National Register of Historic Places. Prior to a COVID-19 pandemic temporary closure of the house, public tours were available. Nancy Caroline Hanley was the oldest surviving Hanley daughter. She remained in the Hanley House until her death in 1938 at age 97. Clayton officials purchased Hanley House and roughly one acre of land in 1968 from Barbara Yore, a granddaughter of Martin and Cyrene Hanley.
The City of Clayton was formally incorporated in February 1913, named after Ralph Clayton, who settled in the area in the 1830s and donated land for establishing the courthouse. On Dec. 4, 1877, St. Louis County residents voted to adopt Clayton's and Hanley's land as the new County seat. The first schoolhouse of Clayton was established in the early 1880s.
The architecture of central Clayton is said to reflect the city's economic activity and eras of growth, with mid-century Modernist low- and high-rise structures contrasting with earlier mansions, stores and flats. Research for this feature by Missouri Historical Society Library & Research Center library and archive specialists indicate the oldest subdivisions in Clayton that are described on the National Register are: Wydown-Forsyth district, which includes the Chancellor's House, 6500 Forsyth Blvd., built in 1909; several homes built in 1912, including 5441 and 6457 Cecil Ave.; 6444 and 6464 Ellenwood Ave.; 6440 Forsyth Blvd.; Brentmoor Park, which includes at least one house built in 1911; and the Haarstick-Whittemoure Houses from 1912.
