All known 18th-century iterations, Ms. Allen said, show the signatures grouped by state, with some printers even adding state labels. But here they were all jumbled. “I just kept staring at it,” she said. “There was no discernible order.”
But then she labeled each name with the number of the column it appeared in on the 1776 parchment, and noticed that they alternated in a clear pattern — a pattern, she and Ms. Sneff argue, created with help from a well-known 18th-century cipher.