answers: 1971
context: redeemable in gold, the only difference between them and Legal Tender Notes was that the first were liabilities of the Federal Reserve while the latter were direct liabilities of the United States Treasury Department. The $2 and $5 were issued through 1966, and the $2 note was only available as a United States Note. In 1966 the $5 United States Note was discontinued and the $2 denomination was discontinued altogether. In 1966 a $100 US note was issued to meet legal requirements about the amount of notes in circulation. In 1971 the production of US notes was halted and they </s> Philadelphia in 1837 and New Orleans in 1838 and lacks stars on the obverse. In 1838 a semicircle of 13 stars was added around the obverse border, and this basic design was used through 1859. In 1853, small arrows were added to each side of the date to reflect a reduction in weight due to rising silver prices, and the arrows remained in place through 1855. The arrows were dropped in 1856, with the earlier design resumed through 1859. In 1860, the obverse stars were replaced with the inscription UNITED STATES OF AMERICA and the reverse wreath was enlarged. This </s> notes were reintroduced for 1 and 2½ guilders. Silver certificates were issued between 1878 and 1964 in the United States as part of its circulation of paper currency. They were produced in response to silver agitation by citizens who were angered by the Fourth Coinage Act, which had effectively placed the United States on a gold standard. The certificates were initially redeemable for their face value of silver dollar coins and later (for one year – 24 June 1967 to 24 June 1968) in raw silver bullion. Since 1968 they have been redeemable only in Federal Reserve Notes and are
question: when did they stop using silver in half dollars