Thirty-nine men signed a four-page charter in Philadelphia on September 17, 1787, without knowing whether a single state would ratify it — the document has outlasted every government modeled on it since.

The men who filed out of the Pennsylvania State House on the afternoon of September 17, 1787, had just finished the longest closed-door meeting in American history. Four months, one Philadelphia summer, windows shut against eavesdroppers the entire time.

Nobody outside the room knew what they had written.

What actually happened that day?

Fifty-five delegates had shown up to Philadelphia in May, sent by their state legislatures to fix the Articles of Confederation, a wartime governing document too weak to tax, too weak to raise an army, too weak to stop states from feuding with each other over currency and tariffs. By September, only 42 remained, and the plan to patch the Articles had quietly become a plan to replace them.

On the last day, the finished text was read aloud one more time. Benjamin Franklin, at 81 the oldest man in the room and too frail that summer to trust his own voice, had written a short speech urging the delegates to sign despite their doubts; he had a colleague, James Wilson, read it for him. According to notes taken by Virginia's James Madison, Franklin closed by describing the sun carved into the back of George Washington's chair, which he said he had watched all summer without being able to tell whether it was rising or setting. Now, he said, he knew it was rising.

It's a good story, and it comes from a single source: Madison's own convention journal, which he kept in secret and did not publish until after his death in 1836. No official transcript of the debates exists, because the delegates had sworn themselves to secrecy and burned nothing but also recorded almost nothing for the public record. Historians treat Madison's notes as the best account of what was said in that room, not a court reporter's transcript of it.

Of the 42 delegates present, 39 signed. Edmund Randolph, George Mason, and Elbridge Gerry refused, each objecting that the new government gave the presidency and the federal courts too much power and the people too few guarantees against it. Rhode Island had sent no delegates at all; its legislature considered the whole convention illegitimate and stayed home for all four months.

Who actually wrote the words on the page?

The convention argued in broad strokes; a smaller Committee of Style turned those strokes into sentences. Gouverneur Morris, a Pennsylvania delegate with a gift for prose and a wooden leg he'd worn since a carriage accident years earlier, did most of the final polishing, including the Preamble. James Wilson's earlier draft had opened with "We the People of the States of..." and then listed all thirteen; Morris cut the list and left the phrase that mattered: "We the People of the United States." One state, not thirteen bargaining parties.

Once the wording was settled, someone still had to put it on parchment in a hand steady enough to survive the ages. That job went to Jacob Shallus, an assistant clerk to the Pennsylvania General Assembly, who is thought to have spent about 40 hours engrossing the roughly 4,400 words onto four sheets of parchment for a fee of $30. He is not known to have left behind so much as a diary entry about the most consequential copying job in the country's history; his name survived only because the Assembly kept its own payment records.

Why the signing wasn't the finish line

Signing a document in a room is not the same as putting it into force. The Constitution said as much in its own text: it would take effect once nine of the thirteen states ratified it, and each state had to hold its own convention to decide. That process took almost a year and turned violent in argument if not in the streets — Anti-Federalists in New York and Virginia mounted serious opposition, and the promise of a bill of rights, absent from the document Shallus had engrossed, was what finally swung several holdouts. New Hampshire supplied the ninth ratification on June 21, 1788. The new government didn't actually convene until the following March.

So September 17 marks something narrower than "the Constitution became law." It marks the moment the people who wrote it agreed, however reluctantly in three cases, that this was the version they were willing to defend in public.

Congress made that date official only in 2004, when a floor amendment from Senator Robert Byrd designated September 17 as Constitution Day and required any school or university receiving federal funds to hold some form of educational program about the document on or near that day. The single surviving engrossed copy (the one Shallus wrote out by hand) now sits in a bulletproof, humidity-controlled case at the National Archives in Washington, alongside the Declaration of Independence and the Bill of Rights, under lighting dim enough to keep the ink from fading further than two and a half centuries already have.

What the document still has to answer for

None of this settles what the document actually means in any given dispute, which is the argument that has run continuously since 1787 and shows no sign of concluding. Originalists and living-constitutionalists disagree about how much weight Morris's phrasing or Madison's notes should carry in a case being argued today; the text itself is silent on the question of how it should be read, which is perhaps the one point every faction agrees on. The convention that produced it was never public, its full debates survive only through one participant's private notes, and the clerk who wrote the final copy left no account of his own work at all.

What survives is the parchment itself, and a federal law that sets aside one day a year to argue about what thirty-nine signatures actually bought the country.

Sources

• National Archives, "America's Founding Documents: The Constitution" and related engrossing/Jacob Shallus records
• National Park Service, Independence National Historical Park, "September 17, 1787: A Republic, If You Can Keep It"
• National Constitution Center, "On this day, the Constitution was signed in Philadelphia" and "Gouverneur Morris: Unforgettable Yet Forgotten"
• HISTORY.com, "U.S. Constitution signed"
• Wikipedia, "Signing of the United States Constitution" and "Preamble to the United States Constitution"