Final answer:
Article I of the Constitution is the longest article and establishes the powers and limitations of the legislative branch, reflecting the founders' view of the potential threat posed by Congress. The founders believed in the importance of checks and balances and sought to prevent the concentration of power.
Step-by-step explanation:
Article I of the Constitution is the longest article in the document because it establishes the powers and limitations of the legislative branch, specifically Congress. The length of Article I reflects the importance the founders placed on Congress as a branch of government and their belief that it posed the most significant threat to individual liberties if not properly restrained. By clearly defining the powers and limits of Congress, the founders sought to prevent the concentration of power and ensure checks and balances among the branches.