Football coach responsible for devising the double-wing formation, the “Pop Warner League” is named in his honor. Vintage ink signature, “Glenn S. ‘Pop’ Warner,” on a light green 4.5 x 1 slip, affixed to a slighty larger off-white sheet. In fine condition, with a light vertical fold through a single letter of signature, and a couple adhesive wrinkles. Auction LOA Steve Grad/PSA/DNA and R&R COA.
