Exceedingly scarce pin from the 1896-97 Whitehead & Hoag set, commonly known as "Cameo Pepsin" due to the advertisement sometimes present on the reverse of the pins (though the pins are often found with or without Cameo Pepsin advertising). The first large set of pins to feature baseball players, more than 140 subjects are known and more are added to the checklist as they are discovered. Typically subject to image fading and other condition flaws due to age, the pins are quite condition sensitive today. 

The only example of Sadie McMahon's pinback graded by PSA, the VG 3 assessment speaks to a slight bit of foxing on the surface and some mild soiling to the paper backing.  Image fade is noticeable, with slightly below average contrast, but overall, an attractive pin from a desirable set.