The primary purpose of the Constitutional Convention, which took place in Philadelphia in 1787, was to amend the Articles of Confederation. The Articles were found to be weak and ineffective in managing the affairs of the newly independent states, leading to various problems such as economic instability and lack of a strong central government.
However, as the convention progressed, it became clear that simply amending the Articles would not suffice. The delegates ultimately decided to create an entirely new framework of government, leading to the drafting of the United States Constitution. Therefore, while the original intention was to amend the Articles of Confederation, the outcome was the establishment of the Constitution.