Final answer:
Amending the Articles of Confederation was difficult because it required unanimous consent of all states, which was hard to achieve compared to the three-fourths ratification requirement for the U.S. Constitution.
Step-by-step explanation:
The reason it was difficult to amend the Articles of Confederation is because amendments required the unanimous consent of all the states. This stringent requirement made it nearly impossible for the government to adapt or improve the Articles, as securing unanimous agreement among all thirteen states proved to be an insurmountable obstacle. This contrasts with the current U.S. Constitution, which only requires a two-thirds majority in both houses of Congress and ratification by three-fourths of the state legislatures.