On Saturday afternoon, 15 September 1787, near the end of the Constitutional Convention, the delegates approved the final draft of the Constitution and ordered it engrossed on parchment to be ready for signing on Monday morning, 17 September. The Convention selected Jacob Shallus, the thirty-seven-year-old assistant clerk of the Pennsylvania Assembly, to be the calligrapher. Shallus was probably recommended for the job by Thomas Mifflin, a Pennsylvania Convention delegate who, as Speaker of the Pennsylvania Assembly, had signed many acts engrossed by Shallus. Not only was Shallus experienced in engrossing official documents, he was readily available because the Pennsylvania Assembly was meeting upstairs in the state house (now Independence Hall) having allowed the Constitutional Convention to meet in the more spacious and accommodating first floor chamber. For 150 years, historians weren’t aware of the identity of the transcriber until research done during the sesquicentennial celebration of the Constitution in 1937 identified Shallus.
Shallus (1750–1796), the son of German immigrant parents who had settled in Pennsylvania in 1749, was a merchant in Philadelphia, who was listed as a “gentleman” in the tax rolls. In 1771, he married eighteen-year-old Elizabeth Melchior and they had eight children. Sympathetic to the American cause, Shallus sold his business and enlisted in the army serving as a quartermaster in the First Pennsylvania Battalion during the disastrous Canadian campaign of 1775–1776. Shallus resigned his ensign commission in January 1777 and became a deputy commissary general for Pennsylvania. He also partnered in outfitting the privateer Retrieve. Presumably with the profits from this investment, Shallus purchased a house and a lot in Philadelphia, 147 acres in nearby Bucks County, and 50 and 2000 acres in western Bedford and Northumberland counties, respectively. After the war, in 1783, Shallus was appointed assistant clerk of the Pennsylvania Assembly, a position he held for several years. In late September 1787, the Assembly ordered Shallus as assistant clerk to return two Antifederalist seceding assemblymen to the chamber so that a quorum could be reestablished that would allow the completion of the call of a ratifying convention. Shallus later became assistant clerk of the Pennsylvania constitutional convention of 1789–1790.
The Confederation Congress paid Shallus $30 for the transcription of the Constitution on four sheets of parchment measuring 28-3/4 inches by 23-5/8 inches. Using a goose quill and black ink made of iron filings in oak gall that later turned brownish, Shallus wrote over 25,000 letters in nearly 4,500 words, completing the arduous process on Sunday, 16 September, in time for the monumental signing the next day. On an additional half sheet of parchment, Shallus also engrossed two resolutions approved by the Convention calling for Congress to transmit the Constitution to the state legislatures which would then call ratifying conventions and suggesting the procedure for implementing the Constitution after ratification by nine state conventions.