UX5 with Sing Sing, NY CDS and famous "backward 5" fancy cancel - 1875

Request from a Sing Sing merchant about the status of a flour order. While there is no current post office with the specific name "Sing Sing, NY," the location is served by the Ossining Main Post Office. Historically, the village was named Sing Sing, and mail was postmarked with that name until the village was renamed to Ossining in 1901 to distance itself from the notorious Sing Sing Correctional Facility.