The 1915 ten dollar bill Federal Reserve Bank Note is a tough note to find especially in high grades. These notes were meant to drive out the circulation of national currency but the Federal Government overestimated the national banks willingness to give up their private currency (and float). Because the national bankers were unwilling to redeem these 1915 ten dollar bills weren't issued in great numbers. This lack of issuance makes them kind of scarce today. They can be found but they aren't common. If you have a 1915 $10 dollar bill please send me an image and I will be happy to estimate your note.