Final answer:
Article III of the U.S. Constitution established the judicial branch.
Step-by-step explanation:
The article in the U.S. Constitution that established the judicial branch is Article III. This article outlines the powers and responsibilities of the judiciary in the United States. It establishes the Supreme Court as the highest court and gives Congress the power to create lower federal courts. The judicial branch plays a crucial role in interpreting laws and ensuring justice in the country.