The History of United States Coinage As Illustrated by the Garrett Collection

Harper was apparently encouraged in this proposal, for at a later time Elias Boudinot persuaded legislators to appropriate $100 to compensate Harper for dies in his possession. Presumably samples were made in 1795 to demonstrate Harper's ability. Numismatists today believe that the so-called 1795 Jefferson Head cents, coins which bear a distinctive portrait unlike that used at the Philadelphia Mint, were Harper's work.

Periodic visitations of yellow fever wreaked havoc on the operations of the Mint during the early years. Of all the eastern cities Philadelphia in particular seems to have been severely afflicted. The reputation of Philadelphia in this regard was such that several other locations prohibited visitors from Philadelphia from passing through. At the time the source of yellow fever had not been traced to mosquitos, and many widely varying theories were proposed.

In 1793 yellow fever claimed the lives of Joseph Wright, the engraver, and Joseph Whitehead, who worked in the assaying department. The Mint was closed because of yellow fever from September 1 to November 7, 1797; from August 20 to November 1, 1798; from September 20 to November 1, 1799; and September 24 to about November 1, 1803.

Director Boudinot, on August 24, 1799, prepared instructions for closing the Mint against the epidemic. The provisions specified, among other things, that all bullion and expense accounts were to be closed before August 31st and workmen were to be paid. Gold and silver given by the treasurer to the coiner were to be produced into coins as fast as possible, deposits were to be paid, any remaining bullion was to be stored in vaults (distant from the Mint) so that the Mint closing without a guard on hand would give no problems, all officers were to return to the Mint any coins, clippings, or other items they had belonging to the Mint, machines were to be prepared for the hiatus and presses were to be dismantled. Unusable dies were to be destroyed, and usable dies were to be put in strongboxes in the Bank of the United States. Other small Mint property and records were also to be stored with the same bank. Mr. Eckfeldt was to take care of pasturing the Mint horses. At the time, coins were struck by the use of hand presses. Horses provided power to operate rollers used in planchet preparation.

In turn, the Mint employees signed a promise to come back to the Mint once the fever had ended:

We, the subscribers, do hereby promise and engage to return to the service of the Mint as soon as the same shall be again open after the prevailing fever is over, on the penalty of twenty pounds. As witness our hands this 31st day of August, 1799.