The 1915-S Lincoln cent is a scarce semi-key in circulated grades but is one of the toughest coins to locate in Mint State grades. The reason for this is that very few of these coins were saved by collectors during the time when these coins were new; simply wasn't en vogue yet to save uncirculated branch-mint Lincoln cents in part because there was little incentive to do so during a time before coin albums and coin displays reached the masses.