Glenn R. Rupert Jr. earned his teaching degree in science from Bloomsburg University in 1965, and began his career teaching science at Clark Lane Junior High School in Waterford, Connecticut.

His love for wrestling inspired him to start a youth wrestling program that year, which led to him being offered the position of head wrestling coach at the high school. This prompted him to return to school to gain his mathematics degree, so that he could both teach algebra and be the wrestling coach at Waterford High School. Due to the youth program he had started, more incoming freshmen started coming out for wrestling at WHS and the program began to grow.

Waterford won their first Eastern Connecticut Conference wrestling tournament in 1971 and went on to win the Connecticut state team title in 1985 while also finishing second four times. During his 20-year career, Waterford produced 44 ECC champions, nine sectional champions, 24 Class M / Class L state champions and nine state open champions.

The state wrestling poll began in 1983 and Waterford finished ninth in 1984 with a 17-6 record, ninth in 1985 with a 16-7 record and third in 1986 with an 18-3 record. Rupert finished with a career record of 201-124-3 for a winning percentage of .615.

Rupert was named Connecticut Coach of the Year in 1982 and was nominated for the National High School Coach of the Year award and honored for 20 years of outstanding service by the United States Wrestling Association in 1987. He was inducted into the Connecticut Wrestling Hall of Fame in 2005 and into the Waterford Athletic Hall of Fame in 2010.

He was also an assistant soccer coach and directed plays in the yearly One Act Play competition.

Most important of all in his teaching and coaching career, he was proud of the positive influence he hoped he had on his students' lives.