Collecting autographs is a time-honored avocation that has exploded in popularity in recent years, creating a new industry with millions of autographed items for sale online. Coveted signatures include those from presidents of the United States, Civil War officers, World War II heroes, classical music composers and baseball stars. It is estimated that 90 percent of historical autographs on the market today are forgeries. This book provides a definitive guide to signature authentication for experts and beginners alike. Numerous illustrations of genuine and forged signatures are included, from Ty Cobb to Isaac Newton to Abraham Lincoln to Neil Armstrong. Detailed descriptions of common forgeries are given, enabling collectors to make direct comparisons.