If you're thinking Washington,
D.C. then think again, Washington was the last, becoming the capital of the
United States on November 17 1800.
Instead we'll let you take your pick from the following
Pennsylvania was the first capital under the First Continental Congress from
September 5, 1774 to October 24, 1774.
Baltimore, Maryland was the first capital under the
Second Continental Congress from December 20, 1776 to February 27, 1777.
Philadelphia, Pennsylvania was the first capital under
the Articles of Confederation from March 1, 1781 to June 21, 1783.
New York City was the first capital under the Constitution
from March 4, 1789 to August 12, 1790.