Knapp was a founder of the West Virginia 4-H Clubs, and he was recognized nationally and internationally for his work in rural education for both youth and adults. He was also instrumental in promoting programs for rural electrification in West Virginia. He was a pioneer in the establishment of the National 4-H Club Center, and he was one of the original incorporators of the National 4-H Club Foundation.

Honors & Activities
- J. O. Knapp served 45 years in West Virginia Cooperative Extension as County Agent, District Agent, and Director.
- He was a pioneer in the establishment of the National 4-H Club Center.
- He was one of the original incorporators of the National 4-H Club Foundation and served as chairman of the Incorp-oratory meeting.
- He helped locate the site for the Center and co-signed the bank loan to acquire the property.
- He served as chair of the Board of Trustees of the National 4-H Club Foundation.
- One of his most memorable occasions was participating with President Eisenhower at the dedication of the National 4-H Center.
- Knapp chaired the 1960 conference on Effective Utilization of Private Support for Extension Youth Work.