We have always been told that Thomas Jefferson was the author of the Declaration of Independence, but it turns out that we may be giving Jefferson a bit too much credit. According to ushistory.org the first draft of the document was done in the handwriting of John Adams. The committee appointed by the Continental Congress to prepare the declaration was made up of Jefferson, Adams and Benjamin Franklin. After the first draft had been written by Adams the committee turned it over to Jefferson to do the editing. On the ushistory.org website you can see Adams' draft and compare it to the next draft which was done by Jefferson. There was quite a bit of editing done, but most of the language and certainly the main points covered (mostly complaints about the conduct of King George III) were contained in the first draft by Adams. Even after the Jefferson version was adopted by the committee and presented to the Congress, a few more changes were made in the language of this historic document. So when we are told that Jefferson is the author of the Declaration of Independence, this is true---sort of.
Another interesting tidbit about Independence Day is that it was not until 1941 that the day became a paid holiday for federal employees. Happy 4th, everyone!