Born in Waterbury, Connecticut, and raised in Union City, Gereski graduated from Sacred Heart High School in 1953.
His thesis was entitled “Can the Reserve Components Perform as Adequate Backup Force to Active Components in the 1980s?” Colonel John T. Gereski was recalled from his position at the Pentagon by Governor William A. O'Neill on March 18, 1985, to complete the unexpired term of Major General John F. Gore, who was forced to resign as Adjutant General due to improper behavior.
During his second full term as Adjutant General, he oversaw the largest mobilization of Connecticut National Guard forces in forty years due to Operation Desert Storm.
MG Gereski had been reappointed to a four-year term just six months prior to Weicker taking office as governor.
They retired to Fairfax Station, VA to be close to family and a vacation home on the Chesapeake Bay.