Knapp became a blue lodge freemason in the winter of 1900, taking the three degrees between 21 September and 1 December at Norwood Lodge, in Cincinnati, then took the four principal Scottish Rite degrees between 4 November 1913, and the 29th January 1914. He remained a member of Cincinnati Scottish Rite until his death. Freemasonry passed down the generations – when Ethel Knapp Behrman died suddenly on Sunday 20 June 1943 her obituary in the Cincinnati Enquirer recorded her membership in the Order of the Eastern Star, an initiatory organization for the wives of masons.
