The Schlessman Family Foundation was founded in 1956 by Gerald L. and Florence M. Schlessman. The foundation was established to provide charitable support by granting opportunities for children and adults hindered by economic status, physical or mental challenges, or requiring additional educational opportunities to enable them to become self-sufficient, productive community members. Since its inception, the Foundation has contributed over $150 million to more than 1,000 charities.

Upon the death of their parents, Lee E. Schlessman and Susan Schlessman Duncan assumed the leadership of the Foundation and continued until they passed away in 2019.

In March 2026, Schlessman family members came together to celebrate the 70th anniversary of their families legacy at the Denver Zoo.