Why the declaration of independent would be a effective tool

the Declaration of Independence is an important and an effective tool because according to the "Center for Civic Education" is stated the following:

"We hold these Truths to be self-evident, that all Men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty, and the Pursuit of Happiness"

In other words since the U. S. A became independence, the human rights were important for them. They took the time to take a look in what they needed to improve to make the beautiful country that we see today.