Postal service was established in Adair on January 2, 1874, with John E. Moran appointed first postmaster. After occupying a number of local storefronts, the post office moved to its present location in 1946. A new counter and lock boxes were installed in 1959, with significant remodeling completed in 1967.
The cornerstone of the present Adair County Courthouse was laid in downtown Greenfield on July 4, 1891. The cornerstone features historical items including a bible; bottles of wine, corn, and oil; the history of Greenfield; and a letter to be opened by the oldest man present when removed. The $27,000 courthouse was designed by S.E. Maxon of Council Bluffs, the firm which also designed the Fremont County Courthouse in Sidney.
The single-screen Graind Theatre in Greenfield was constructed in 1927, at a cost of $15,000. Considered state-of-the-art at time of construction, the theatre featured a number of amenities including sloping floors, comfortable seats, and air conditioning. The theatre shows first-run movies daily except Mondays, with matinees on Saturdays and Sundays.