The Articles of Confederation was ratified in 1781 and was known for having very many weaknesses. With these Articles, the federal government had little to no power, which rendered the country to be weakened.
The federal government could not tax the states. During this time, the government had to rely on taxes to pay war debts and better equip the country, but the Articles of Confederation made it so that the government could not tax the citizens. They had to directly ask the states for money instead, which usually meant they weren't going to get any.
The federal government could not regulate trade. Regulating trade was very important during this time, as trading was a big source of income and many people relied on trading to get certain products and items from overseas. The federal government could not regulate the trade properly, which would cause disputes to break out among the states because they could not create trade policies with other countries.
The federal government could not create and enforce laws properly. With the Articles of Confederation, the government only had one branch, which was Congress. This meant they had trouble enforcing laws onto the citizens. In order to pass a law, 9 out of 13 of the colonies had to approve of it. This usually meant that no new laws were being passed and the states could do what they wanted a lot of the time.