From Croton Water to Public Works
After the arrival of regular water supplies with the Croton Aqueduct, the areas above 59th Street began a tremendous increase in building and development. Not all areas however were done at once, and one scam utilized by the famous Tweed Ring was to buy up properties with the fore-knowledge that these streets would be the first to get water and sewers. The head of the Department of Public Works was indeed William "Boss" Tweed himself.
This cover was one of the first to have the florid, almost badge-like quality, meant to be a sign to property owners that this area had top notch facilities and who they were provided by. Note the almost crown-like D P W.
These covers are still scattered about on many streets of the Upper East and Upper West Sides of Manhattan. This one is on Riverside Drive at 113th St.