Why did colonists feel the Articles of Confederation were necessary even though the Declaration of Independence was
already written?
The Declaration of Independence outlined a system of government but did not specify how much power that government
could have.
The Declaration of Independence determined individual rights but did not discuss how those rights influenced others.
The Declaration of Independence called for a federal system of government but did not plan for the role of individual
states.
The Declaration of Independence outlined a relationship between individuals and the government but did not detail the
power and control of that government.

The Declaration of Independence called for a federal system of government but did not plan for the role of individual  states.

Explanation:

Articles on Confederation  came into force in 1781, as an interstate treaty of friendly union of sovereign states. The common body of the federation is the Confederate Congress to which each state sends its delegation, and each has one vote, regardless of size and population. Delegations of states are bound by an imperative (binding) mandate, which means that they cannot decide on their own behalf but solely according to the instructions of their state. States themselves regulate the position of their representatives, the way they are elected, the number of members, the recall, etc. Congress elects a Committee of States, consisting of one representative from each state, who does business when Congress is not in session. Congress decided the most important issues by a two-thirds majority of all states. Decisions bind states, but not their citizens. The Alliance, like any of the states, has the right to intervene in international relations. Articles on Confederation were adopted and could only be amended by unanimous decision of all Member States. States are also entitled to withdraw from the confederation.