By 1960, suburban sprawl had completely engulfed Bethpage. Compared to the more open land of the 1930s-1950s, Grumman was now surrounded by single family residential houses. This 1960 aerial photograph shows the property. Note that the open land in the upper left area was Grumman property, but not developed yet. This would later become the site of additional buildings, and the corporate headquarters. map Left: Map of the entire Grumman facility in 1965(5). The open land along Stewart Avenue would remain unused until the 1980s. The increase in defense spending during the Reagan years provided an influx of cash to construct a new corporate headquarters along Stewart Avenue in the 1980s.The new building was 525,000 square feet and contained a 175 seat auditorium, 500 seat cafeteria, retail space, and an atrium(6). Today it is the headquarters of Cablevision.

Grumman provided thousands of jobs to the Bethpage community, and voters tended to pick politicians in favor of defense spending. During the 1980s, Grumman was the largest single employer in Nassau County. The facility in Bethpage included it's own Long Island Rail Road stop to bring in workers from outside the immediate area. Grumman also was philanthropic in the community and donated land to the Town of Oyster Bay for a community park.

However, there was also a dark side to Grumman's link with the community. For decades Grumman had sprayed chemicals called chlorinated hydrocarbons on metal prior to painting them. This acted to clean the metal. This spray started to leech into the soil, and by the 1970s had been noticed by Grumman employees. Grumman had it's own water connection to the aquifer under Long Island. Employees reported that the tap water tasted and smelled bad. A study found that the water supply was contaminated, and Grumman switched to using Bethpage Water District water. By the 1980s, this contamination had reached a Bethpage District pumping facility. Grumman agreed to pay the costs of clean the clean up. In the 1990s the land dedicated as a park was found to have high levels of chemicals, and was closed for several years for cleanup.