Wagner Typewriter Co./Pan-American Exposition/Buffalo 1901. Printed corner card on gorgeous all over multicolor advertising design for the Pan-Am Expo. showing "Niagara Falls" on cover franked with 1901 1¢ Pan-Am tied by Buffalo, N.Y. Pam-Am publicity machine cancel, cover with light vert. fold, Very Fine. Estimate  $200 - 300. $0 (Image)