Nicholas "Nick" H. Grosz, Jr. was born in Brooklyn, New York to Nicholas and Helen Grosz. He was a 1958 graduate of Hackensack High School where he lettered in football and baseball. He attended the University of Rhode Island where he was a football player for four years and a member of Phi Gamma Delta Fraternity. During his freshman and sophomore years, he participated in the Army ROTC Program and spent two summers in the USMC Platoon Leaders Course in Quantico, Virginia. He graduated in June 1962 with a Bachelor of Science Degree in Physical Education and was commissioned as a Reserve Second Lieutenant, United States Marine Corps.
In 1962, LT Grosz was assigned to the Fleet Marine Force at Camp Pendleton, CA, where he deployed to Okinawa and then to the Republic of South Vietnam to train the Vietnamese Marines. He received a regular commission in June 1965 while serving in Vietnam with the First Marine Division, 2nd Battalion, 7th Marine Regiment. It was during this combat assignment that he was awarded the Vietnamese Cross of Gallantry in May 1965. He received a Purple Heart for wounds sustained during his second combat tour and was awarded the Bronze Star with Combat "V" for valor. He was awarded the Navy Cross for his actions on December 18, 1965, during Operation Harvest Moon. He was awarded a Bronze Star in July 1970 for combat action during his third tour of duty in Vietnam.
After returning from his first tour of Vietnam in 1966, Grosz had numerous command and staff assignments culminating as the Commanding Officer, 27th Marines. His final military assignment was in Washington, DC, where he served as Director, Human Resources Division, HQMC. He was awarded the Legion of Merit upon his retirement in February 1990, retiring as a Colonel.