The Declaration of Independence was a...

"Hey, any of those old ass Royal contracts you used to abuse and fuck us over with...this is a declaration of independence from allegiance to any other than our own country and its fellow countrymen, and we have no obligation to anyone now!"
...document of foundation to build a country on.

The Constitution of The United States of America was a contract we shoved in the face of ANY governing agency who would brave the task of representing such a boldly defiant and rebellious nation sworn to the literal death to preserve that status, and told them in no uncertain terms...

If you dare govern us, this "will be" without exception the strict standard of conduct or we will come for you. There is no option, this be the charter you adhere and swear an oath under law to under penalty of death.

We used to be a bunch of scary motherfuckers...what happened to us?