The Declaration of Independence and the Constitution pretty clearly follow Locke's ideas.  The Articles of Confederation do so, but much less explicitly.

Locke's major idea was that the point of government was to protect the life, liberty, and property of the people.  People willingly give the government sovereignty over them so long as the government protects these rights.  The Declaration lays out this role of government and the fact that it gets its power from the people quite explicitly.  The Constitution (as well as the Bill of Rights) again states this idea.  The 5th Amendment, for example, guarantees that people's liberties cannot be taken away without the due process of law.  By contrast, the Articles included no explicit guarantees of rights.  Instead, they left that to the state constitutions.  The Articles wanted to protect people from government tyranny, but they did so by making a government that was generally weak.

In this way, all of these documents, to some extent or other, reflect Locke's ideas.