The DT 20, also known as a Die Trial or Pattern coin, refers to test strikes made to evaluate new designs or coinage concepts before mass production. The 1861 DT 20, specifically from Denver, Colorado, is a notable example of such trials conducted during a period of significant change in the U.S. Mint system. These coins are typically produced in limited quantities and are highly collectible due to their historical significance and rarity in numismatic collections.

Item Denomination Series Year Mint
1861 DT$20 Clark Gruber Copper Die Trial DT$20 Patterns & Die Trials 1861 Denver, Colorado