Silver proof coins are coins minted as samples or specially manufactured for collectors or archival purposes. Proof coins are produced with chemically treated dies that cause sharper edges. Unlike regular coins, proofs are double struck, giving them high definition.
The U.S. Mint produced proof coins regularly through 1916, however, as of 2014, they generally only create silver proof coins for collector's sets, such as the American Eagle, America the Beautiful, 2014 Civil Rights Act of 1964, 2013 Girl Scouts of the USA Centennial, 2012 Infantry Soldier and 2010 American Veterans Disabled for Life silver proof coins. Due to the smaller numbers produced, collectors value old proof coins.