According to Mary Cheever in her wonderful book on Briarcliff Manor: The Changing Langscape:

The “Century Homestead” as it is named in the Beer’s Atlas of 1867, on Chappaqua Road has been called the Reuben Whitson House. However, since there are no Whitsons on the Mt. Pleasant census rolls before 1830, it was probably another Washburn House (cf. The Washburn House).

Taken with a Sony A7IV and Sony FE 28-70 f3.5-5.6 OSS.