On July 2, 1776 the Continental Congress declared the colonies to be free and independent states. That July 4th thing? That's the day they adopted the Declaration of Independence. They ordered the document to be printed. Then, on July 19th they ordered that it be engrossed (formally printed for signature), then they waited for the engrossers to do their thing. They signed it on August 2nd.
This is properly the holiday weekend. We current Americans, we who are spoiled to instant communication and WYSWYG printing aren't familiar with the concept that it might take days or weeks to get a document from one place to another. There wasn't any Xerox machine in those days, no faxes, no phones. If you wanted a document, someone had to set the type and print it. If you wanted a document formally engrossed, guys sat down with pens and parchment and wrote it out by hand.
But, today is the day we declared independence by adopting the Lee Resolution.
On this day in 1863, Henry Lee's kinfolks, Bobby, launched attacks against the Union flank at Gettysburg. He sent Ewell to hit the fish hook, with Hill demonstrating against the center. His main thrust was with Longstreet and John Bell Hood against the southern flank. On top of a small hill, the 20th Maine stands wondering what's going to happen next. Before the day is over, Joshua Chamberlain will have won a Medal of Honor.