The Constitution of the United States
Examples
Justice in the Court
With the Articles of Confederation, criminals in court may not get the right to hire lawyer or to speak against what they are being charged of.
The Sixth Amendment from the Bill of Rights ensures the criminals to have the right to silent, hire lawyer, and speak against what they are being charged of.
Presidential Power
With the Articles of Confederation, president has controlled on the Congress, in which if the power is being used in wrong way, there is almost nothing can stop that.
The Constitution divides up to three separate powers, the legislative, judicial, and executive branches. With these powers, one can "veto" another if disagree with the decision.
Before the American Revolution, there are cases in which people get searched unreasonable.
With the Fourth Amendment, the U.S Citizens have the right to secure their private belongings, and unreasonable search shall not be violated.
Unreasonable search and seizure