Answer:
The Articles of Confederation were the first constitutional foundation of the United States and the forerunner of the Constitution of 1787. Their regulations were essentially based on the principle of national sovereignty. After the Continental Congress passed them on November 15, 1777, they were in force from 1781 to 1789 after their three-year ratification.
The provisions of the Articles of Confederation were based on the principle of complete sovereignty of the individual states. In a way, they established an American confederation, which, however, had some structural deficiencies and quickly failed because of them.
From the outset of the Confederation, its legislature, the Continental Congress, was not allowed to levy its own taxes. Contributions from the member states should contribute to the functioning of the Confederation organs, however most member states did not comply with this convention. For this reason, the Confederation was unable to guarantee its members military protection against the increasing intervention of the European powers.
In addition, most of the member states did not feel obliged to accept agreements made in the Confederation. Since the latter lacked both enforcement and sanction options, the Confederation's scope for action was always limited. A key political-economic obstacle and expression of the fragmentation was, for example, the increasing delimitation of the member states by protective tariffs, which the Continental Congress was also powerless against, because they had the possibility, for example, of leaving the Confederation.
The Philadelphia Convention was convened to address these grievances. Actually, it should initially only advise on the possibility of improvements in the state organization and find a wording for the articles in order to reassure the individual states that feared for their power. In the end, however, it presented a completely new Constitution, which, unlike the Articles of Confederation, required a strong federal government as an executive body in the first place. This should take over the competences of the individual states, particularly in matters of foreign policy, foreign trade and national defense.