Both the Declaration of Independence and the US Constitution have examples of popular sovereignty. Popular sovereignty is the idea that citizens have control over the government in the sense that they get to vote on who they want representing them.
This idea is seen in the Declaration of Independence, as it states "That to secure these rights, Governments are instituted among Men, deriving their just powers from the consent of the governed." This quote represents how the government gets its power from the people, not the other way around.
The Constitution also has examples of popular sovereignty. This is evident when it states "The House of Representatives shall be composed of Members chosen every second Year by the People of the several States." This shows how citizens have the power to elect the members of the House of Representatives.