The New Orleans Mint in Louisiana operated from 1838 through 1861, and again from 1879 through 1909. Coins minted in New Orleans bear the distinctive “O” mintmark and are an important focus for numismatists. The history of the mint and details about its operations are fascinating subjects for study. This article explores this topic and offers some specific information about the manufacturing processes employed during the mint’s years of coin production.
President Andrew Jackson was a military hero based on his decisive victory over British forces at the Battle of New Orleans, at the tail end of the War of 1812. During his presidency he was a proponent of creating branch mints to increase the production of United States coinage. On March 3, 1835 Jackson signed a bill authorizing the construction of three new mints, to be located at Dahlonega, Georgia, Charlotte, North Carolina, and New Orleans, Louisiana. The Dahlonega and Charlotte mints were relatively small facilities and produced gold coins only. Both of those mints closed at the onset of the Civil War and never reopened. The much larger New Orleans mint produced gold and silver coins, in all denominations. Although this facility also closed during the Civil War it reopened in 1879 and continued to manufacture gold and silver coins until 1909.
Historical records include many contemporary references that describe in detail the production processes employed at the New Orleans Mint. From the acquisition of the gold and silver raw material to the eventual shipment of the finished coins, the entire minting operation is a fascinating area of study. The New Orleans mint operated in an era when coal-fired steam engines powered the equipment, horse-drawn wagons were a primary means of transportation, and electricity and the internal combustion engine were just coming into widespread use. The Mint nevertheless developed machines and procedures that allowed the efficient production of coins on a tremendous scale.
The New Orleans mint typically received precious metal in the form of dust, ingots, foreign coins, and old jewelry. The depositor was given a receipt and charged a fee if refining was needed to prepare the metal for coinage. The metal was assayed and the result reported to the mint treasurer. Once the value of the metal was determined the depositor presented his receipt and was paid in US currency.
The refined, alloyed metal was melted and cast into standard-sized ingots which were repeatedly passed through a rolling mill to create metal strip of the proper thickness. The strips were heated and cooled (a process called annealing) as needed to keep the metal malleable. The final thickness adjustment was made at a “drawing bench” where the strips were drawn between precisely calibrated steel cylinders. A vertical steel punch apparatus was then used to cut out the circular coin planchets. Each punch at maximum operating speed could turn out 225 planchets per minute. The strip scrap remaining after planchets were punched out was returned to the furnace for re-melting. In fact, all gold and silver scrap was carefully monitored and controlled, with very little loss.
Female employees were generally hired to sort the planchets to ensure the weights were correct. Light planchets were returned for re-melting while heavy ones were hand-filed to correct the weights. Approved planchets proceeded to the milling room, where they were compressed between a rotating steel wheel and a stationary wall; this created a uniform raised rim on each planchet. Depending on denomination, between 500 and 1200 planchets could be milled per minute. Finished planchets were annealed, washed, and sent to the coining room.
Different coining presses were employed for different coin denominations. Planchets were fed into brass tubes from which they were removed and placed in the coining chamber by steel feeder fingers. The dies closed on the planchet with a force of around 150 tons of pressure to create each coin. The feeders simultaneously grasped the finished coin and the next planchet; the feeder motion then transferred the coin into a collection hamper and placed the planchet into the coining chamber. The rate of coin production was generally about 85 coins per minute, per press.
Finished coins were inspected, weighed, and packaged in boxes. The filled boxes were weighed in the presence of the treasurer. If the weight was correct, the sealed box was placed in a vault. Samples corresponding to each potential shipment were sent to the assay department at the Philadelphia mint for review. If approved, each shipment was made available for coinage orders. If samples were rejected, the affected production run was condemned and re-melted.
During its years of operation (from 1838 to 1861 and from 1879 to 1909) the New Orleans mint produced silver 3-cent pieces, half dimes, dimes, quarters, half dollars, and dollars. With the exception of the 4-dollar Stella patterns, New Orleans produced gold coins in all denominations: gold dollars, quarter eagles, three-dollar gold pieces, half eagles, eagles, and double eagles. The gold and silver coins from New Orleans include many rare and valuable issues. Among these are the extremely rare 1838-O proof half dollars, the 1856-O gold double eagle, and the unique proof 1844-O eagle and half eagle coins. However, many more issues are common and easily within reach for the average collector. The coinage of New Orleans is an important and popular focus for numismatists. Every collector of United States coins should own at least one example struck at the legendary New Orleans mint.