Answer:
The Articles of confederation was the first constitution of US, it was written at a time when people were afraid of national governments. It was created to hold the states to gather and tackle any future attacks. It set up Continental congress at federal level and there was no provision for Judicial and Executive branches at the central level. The states were provided with all the powers which were not reserved for the continental congress.
The Articles had many weaknesses, the lack of power for the federal government made it weak. It was given power to pass laws but it couldn't enforce it. States could also ignore the federal law if they didn't like it. Congress also didn't had power to lovey taxes or regulate trade. Amending the articles also wasn't easy as it could not be ratified unless and until all the states ratified it.
Although it had many weaknesses but it did succeed in holding together the union while all its weaknesses were sorted out later.