 Phelps was a founding member of the American Glaucoma Society.At its first meeting, convened in his honor in Iowa City in 1987, a Hawthorn tree was planted, which still stands outside the ophthalmology department, to commemorate his life and contributions.In a keynote address, Armaly described him as "a prolific contributor of new knowledge" who left a "scientific legacy admirable in its size, variety, and quality," concluding, "There is hardly an area in glaucoma that did not interest him and benefit from his research effort."