What was the first US national government?

The first national government was the Second Continental Congress. It raised funds and coordinated the activities of the various colonies during the Revolutionary War.

The "Articles of Confederation" was not a government but a document, drafted in 1777. They effectively governed the practices of the Congress even before their ratification in 1781. Under the Articles, the US government consisted of only one federal institution - a congress in which each state received just one vote. It was led by an officer they called "a President." Congress had the power to oversee the military. John Hancock was the President of this congress from May 24, 1775 to October 31, 1777.

The Articles of Confederation were replaced by the US Constitution, which was ratified in June, 1788. The following year, the first President of the United States, George Washington, took office.