In 1965, Slinzer became the first person to win both U.S. Target and Field Archery Nationals in the same year. Slinzer began shooting competitively at Penn State University in 1954. In 1963, he won the State Field Shoot, and was named All Event Champion for that year. In 1965, Slinzer won the National Field Title, and between 1966-68 captured the State Target and Field Shoots. Between 1963 and 1982, Slinzer won the State Championship 14 times. One of these championships was won a month after suffering a broken wrist, Slinzer taught himself how to shoot left handed and with a cast on his right hand, still won the championship. Slinzer became the first Ameican to win the World Crossbow Championships and did so with a crossbow he made himself. Slinzer put his name on the archery map with his many championships but was also remembered for his generosity and willingness to help other shooters which earned him the name “Gentleman George”. Slinzer passed away in 2001.