[1] It was designed and built in the mid-19th century by newspaper editor and activist Horace Greeley as one of the agricultural experiments he dabbled in, testing whether concrete would make a good building material for farms.

Frank Clendenin, pastor of a New York City Episcopal church, commissioned architect Ralph Adams Cram to remodel it into their house, which he named Rehoboth.

[3] Aldridge traverses a hill that rises steeply from the west, where downtown Chappaqua is located on one of the few level areas amid this generally hilly portion of Westchester County.

West, at the base of the hill, are Robert E. Bell Middle School[4] and the Church of Saint Mary the Virgin, another Register-listed property that was built by the Greeleys in memory of a daughter who died in childhood.

It is a three-story structure of two-foot-thick (61 cm) load-bearing concrete walls topped with a steep gabled roof covered in shingles.

Fenestration on the west (front) facade consists of three six-over-six double-hung sash windows on both stories, one near the north end and the other two closer to the south.

[2] Just south of a single exposed basement window, wooden steps climb up to enter a projecting gabled vestibule from the north.

In addition to giving his family a quiet and cool place to escape the city during hot summers, he also bought some land in the vicinity to use as a small farm, where he tested experimental agricultural techniques he had become aware of.

He took advantage of the slope of the land to construct a building with entrances at all three of its levels—the top for hay, the second for cattle, and the ground floor for storage and waste removal.

They commissioned architect Ralph Adams Cram, who at that time had just completed the Episcopal Cathedral of St. John the Divine in Manhattan, to remodel the barn into a house.

Clendenin, pastor of another Manhattan Episcopal Church, St. Peter's, suggested the Biblical name "Rehoboth", meaning "wide open place" in Hebrew.

[2] In 1954, a later owner had the stepped gable and shed dormers removed, restoring to some extent the building's appearance when it had been a barn.