[3] Stern began in public service in 1957 as law clerk to Matthew M. Levy, a New York State Supreme Court Justice.

His at-large colleague on the council was Robert F. Wagner, Jr. and the two worked together on many matters, including the sale of neckties emblazoned with the Seal of the City of New York to raise funds for libraries and other public purposes.

The election of Mayor Rudolph W. Giuliani in 1993 brought him back into city government; he was appointed Parks Commissioner, starting January 1, 1994.

According to his employee, and later successor, Adrian Benepe, Stern had an obsession with animal-themed architecture, and oversaw the installation of hundreds of animal structures in playgrounds.

As reported in The Chief-Leader of March 7, 2008 "...the city agreed to pay $21 million to the plaintiffs and their attorneys to settle a lawsuit accusing the Parks Department of racial bias."

[11] While Stern was out of Parks during the David Dinkins NYC mayoral administration, he served as president of Citizens Union, a good government group founded in 1897.

On September 12, 1976, Stern married Margaret Lora Ewing, a pediatrician whom he met at a meeting of the Park Lincoln Free Democrats club on the Upper West Side of Manhattan.