When the United States became a nation in the late 1700s, it was completely different than any nation that had come before it. The people of this new nation had just fought a long and terrible war to win freedom from an oppressive government—England. They knew they needed to set up a government, and they needed to be very careful at this point. This government was going to make and enforce the laws. The nation's founders wanted to make sure that the government served the people and protected their rights. The people of a nation have the right to have a say in their own government. They can choose their leaders and vote about important decisions.
Thomas Jefferson authored the first draft of the declaration, and made changes per Franklin, Adams and the full Congress.
According to the Declaration of Independence, each person has unalienable rights (God given) to life, liberty, and the pursuit of happiness. The word unalienable means that the rights are absolute. No human gave them, and no human can take them away.