The Articles of the Confederation is considered the first constitution of the United States. It established the Union and was created during the Revolutionary War. The Articles of the Confederation was drafted in 1777 by the Continental Congress. The same Continental Congress also passed the Declaration of Independence. The articles established cooperation between the 13 states. The government that the articles established was in favor of the states having their own power. They were afraid of having a strong central government. There was no federal government like we are used to that consists of judicial, legislative, and executive branches.
Under the Articles each of the states retained their "sovereignty, freedom and independence."
The articles went into effect on March 1, 1781 when all 13 states signed the document.