Power during the years of the articles of confederation rested mostly with the:

states

People created a WEAK central government back then so that the states could have the majority of the power because they didn't want another ruler ruling over them. The articles of Confederation were made to be a loose aliance between the states, most people felt loyal to their states, and not the country as a whole. The Articles of Confederation did not work out, the Shay's Rebellion made the congress realise that. So, they created the constitutional Convention to amend the constitution, but the delagates ended up creating a whole new Constitution instead, which is the U.S Constitution. 

Hope this helped

The states or 13 colonies however Congress had the power to declare war, appoint military officers, sign treaties, make alliances, and manage relations with Indians.