The main signing of the United States Declaration of Independence took place on August 2, 1776.
Congress adopted the Declaration on July 4, but the parchment engrossed copy was prepared after Congress ordered a formal version. Most historians conclude that the majority of delegates signed that copy on August 2 at the Pennsylvania State House in Philadelphia, later known as Independence Hall.
The traditional image of every delegate signing together on July 4 is therefore misleading. Some delegates were absent on July 4, and others were not yet authorized or present. Additional signatures may have been added later as delegates arrived or became eligible to sign.
The confusion persists because the engrossed document is dated July 4, and several participants later recalled a July 4 signing. The date of adoption remains July 4, while August 2 is generally recognized as the primary signing date. That distinction is especially relevant during the 250th-anniversary observance.