To find out if your $2 is valuable, check out AntiqueMoney.com or OldCurrencyValues.com. Select the appropriate year of your bill to learn of any variations that exist and determine its value.
Pre-1900 notes can fetch hundreds or thousands of dollars, depending on their condition. The most common of the "large size" bills is the 1917 note, which, in average circulated condition, goes for roughly $40. The red seal bills printed in 1928, 1953 and 1963, resembling those of today are readily available for $2.50 to $5 each in average shape, with star notes and un-circulated bills commanding premiums. Two-dollar notes printed after 1963 are still heavily in circulation and do not carry much demand from collectors, as of 2015.