HomeUS CoinsHow Coins Were Made – 1869 Edition

How Coins Were Made – 1869 Edition

How Coins Were Made - 1869 Edition
How Coins Were Made – 1869 Edition

By Roger W. Burdette, special to CoinWeek …..

Nineteenth-century America was a nation of technological advancement, increasing mechanization, and pervasive fraud on the general public by crooks. These criminals were no less ingenious and persuasive than our modern robocallers and purveyors of weight loss gummy ads. The public also had a very limited understanding of how common items were made and thus were sheep ready for sheering, or maybe some lamb chops.

One of those mysteries was “Where did coins come from?”

For some, this was even more confusing than the source of babies or light from the sun. Popular magazines such as Harper’s Weekly occasionally published stories titled “A Visit to the Mint” or something similar, but even those in the money trade were not completely sure how metal became coins. Therefore, sometime in about 1868 the banking house of Drexel & Company in Philadelphia asked the Director of the United States Mint, on behalf of a correspondent in London, how U.S. coins were made.

The director’s reply is direct and clear, although missing many details we coin collectors love. A few minor adjustments have been made to help modern readers understand some of the references.

Messrs. Drexel & Co.


It is a matter of pleasure, both to myself and to the officers of the Mint, to impart the information requested through you, by your correspondent in London.

Herewith you will receive several pamphlets, containing the Mint laws, the order of business in the Mint, the method of conducting the Annual (Pyx) Assay, and my last Annual Report, just issued. These documents will go a good way towards answering your inquiries. For the rest, I shall partly copy from a manual published in 1842, by our assayers, now out of print; making such additions as our progress has called for.

The preliminary processes, of bringing the gold and silver bullion into a state fit for coinage, by refining, parting etc., are in some countries performed by private refiners. At the Mint of the United States, there is a department, under an office styled the Melter and Refiner, for parting, refining, and standarding [sic] the metals, and casting them into ingots or small bars, suitable for the manufacture of coin. It will not be necessary here to dwell upon our parting process, but merely to say that nitric acid is the agent employed; at the New York office, the process is finished with sulphuric [sic] acid, which is found to be an economical advantage.

Our ingots are about twelve inches long, half an inch thick, and of various breadths to suit the different denominations; an inch and a half being the widest.

Formerly we made trial of the plan of making much larger ingots, as used in France, but returned to the smaller, as possessing very decided advantages.

The ingots are of course tested by the Assayer; and as no gold ingot is allowed to pass, whose fineness is more than a half thousandth variant from the standard; silver ingots may have a variation of one and a half thousandths. These limits are considerably less than those allowed by law, and less than are found in the actual coins of France. All the latest improvements in the apparatus for assays, are in use here; including Field’s gas substitute for the sand bath, and the more recent platinum vessels of Mattbey [sic H.M. Raynor for Johnson & Matthey, London ]. The humid assay of Gay-Lussac, for silver, has been used almost from the time of its invention.

When the ingots are approved, they pass into the Chief Coiner’s department. With the requisite annealings, they are rolled down into thin strips or ribbons, and then the thickness is made more exact by drawing. The draw-bench has been in use here from the earliest days of the Mint, and it is believed that we have priority in that item. It is a very important adjuster of weight. A few planchets are then cut out of the ends, and the weight is tested; if satisfactory, the whole strip is passed through the cutting-press. The strip, now full of holes, goes back to the melting room as “clippings”, or “scissel” as it is called in the British Mint, to be cast anew into ingots. The planchets, resulting from the cutting, are annealed, and whitened or cleaned in a pickle of dilute sulphuric acid, and dried in [basswood] saw dust. The silver pieces are usually drawn near enough to standard weight; the gold pieces are adjusted by hand. There is an economy practiced in this part of the business, in the Mint of London, and perhaps that of Paris, in the use of an ingenious machine, a pattern of which we have, but do not use. Our gold pieces are mostly large (twenty dollars) and the work is neatly performed by female hands, at much less wages than are given to male operatives. The range of variation will be found in the Mint law of 1837, and in some supplemental enactments.

The edge of the planchet is raised by a milling machine, preparatory to striking. This machine is moved by steam, works rapidly, and requires only to be fed by a female operative. The idea was borrowed from a machine used in button factories.

The finishing act is the coinage, which is effected by the steam press which has long been used in France and Germany, but we believe has been somewhat improved upon here. It is a very ingenious and effective piece of mechanism; and although it does not produce the perfect impression of the old-fashioned screw press, it works much more rapidly, and without human labor. It is supplied by a female hand, and a workman watches several presses, to provide for breaks or accidents.

After this comes the counting, which is done by a machine [a counting board] which is really a marvel, for its expedition, accuracy, and simplicity. It was invented by an officer [Rufus Tyler] of one of our branch mints [New Orleans] some years ago (since deceased) after other unsuccessful attempts. This was formerly the tedious duty of many hands; it is now rapidly and easily performed by a single female operative. Whether it has been introduced into other establishments we do not know.

After coinage and delivery, the weight of the pieces is tried, both in quantities and in individual samples, and if satisfactory, they are deposited in the vaults, ready for payments.

Drexel also asked about wastage – that is, how much gold and silver was lost during melting, refining and coining. The number of ounces lost to waste might seem large (after all, 780 oz. of gold is worth almost $1.4 million today), but that is trivial considering almost 1.7 million ounces of gold was processed by the Melter and Refiner in one year.

In regard to the question of wastage; the real waste is somewhat met and counteracted by incidental small gains in the melting and parting, in cases where there is not enough to report, or where gold and silver are economically combined for parting. The allowed limits for wastage will be seen in the Mint laws. The actual waste, according to the last annual settlement, was as follows (the nearest whole oz. of wastage is given):

In the Melter and Refiner’s Department;

On 1,692,000 ounces gold, a waste of 780 ozs.

On 1,222,000 ounces of silver, a waste of 260 ozs.

In the Chief Coiner’s Department;

On 931,000 ounces gold, a waste of 60 ozs.

On 474,000 ounces of silver, a waste of 296 ozs.

The foregoing details seem to include all that is asked for, and are respectfully submitted, by your obedient servant.

[Director of the Mint]

The director’s explanation is probably as good as any other, and in coming from an authority, it likely satisfied Drexel’s British friends.

Over time, details changed, as new equipment and improved processes helped move our coin production away from mystery and into simply another manufacturing process. Electrolytic refining eliminated the old nitric and sulfuric acid processes, and practical moving pictures brought movie house patrons closer to how the mints really operated. With the Coinage Act of 1965, the last in-house mint alloy and casting of coinage ingots ended. Coining money is simpler, faster, less mysterious, much safer, and maybe less prone to our wandering imaginations. Our mirror on the past is always hazy, but letters like the one above help us to better understand our ancestors.

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  1. /* “Our gold pieces are mostly large (twenty dollars) and the work is neatly performed by female hands, at much less wages than are given to male operatives.” */

    Yes, it was a very different era … thankfully now gone.


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