Due to improvements in the silver and gold bullion supply and advances in minting technology, the production of both silver and gold coins increased dramatically in the 1830s. The completion of a new and much larger Philadelphia Mint building in 1833 further supported the mintage and circulation of coins. These conditions prompted Mint Director Robert Patterson to seek fresh designs and hire Christian Gobrecht to assist Chief Engraver William Kneass, who had recently suffered a debilitating stroke. Gobrecht ultimately created the Seated Liberty design employed on most silver coinage of the mid to late 19th century (1836-1891), including the half dime, dime, twenty-cent piece, quarter, half dollar, and dollar denominations. At a time when all coins valued above one cent were minted in silver or gold, the U.S. 5-cent coin was commonly referred to as the half dime since “nickels” had not yet become a reality. Like other Seated Liberty coins, the obverse of the Seated Liberty half dime features Lady Liberty seated upon a rock, holding a liberty pole and cap symbolic of freedom in her left arm and a shield in her right to defend it. The reverse design of the Seated Liberty half dime and dime features a wreath encircling the denomination. This half dime was produced from 1837 to 1873 and cocirculated with the new nickel 5-cent pieces that were introduced in 1866.