The Chief Executive of the United States of America

The "Lost" Presidents [those who were Presidents of Continental Congress or the Confederation before George Washington]

The First Continental Congress
This met in Philadelphia on September 4, 1774. All colonies but Georgia were represented. Each colony had equal voting power. The Congress adopted a Declaration of Rights on October 14, 1774, and claimed that each colonial assembly had the right to make laws governing everything except foreign trade. On October 20 it voted to stop importing from Great Britain, discontinue the slave trade, and stop consuming British and some other foreign products, and stop exports to Britain and the West Indies.
Peyton Randolph of Virginia served as President from September 4 to October 21, 1774, resigning due to poor health.
Henry Middleton of South Carolina was President from October 22, 1774, until the Second Continental Congress started.

The Second Continental Congress
This met in Philadelphia on May 10, 1775, not quite a month after the battles at Lexington and Concord. This body adopted the Declaration of Independence on July 2, 1776, after which it drew up the Articles of Confederation. These were the operating basis for government during the Revolution, but due to significant disagreements over the boundaries between the states they were not fully ratified until February, 1781.
Peyton Randolph of Virginia served as President (again) from May 10 to 23, 1775, but was in poor health; he died later that year.
John Hancock of Massachusetts was the President from May 24, 1775, to October 30, 1777.
Henry Laurens of South Carolina was President from November 1, 1777, to December 9, 1778. He was later captured by an English warship and confined to the Tower of London until the prisoner exchange following the Battle of Yorktown.
John Jay of New York was President from December 10, 1778, to September 27, 1779. In 1783 he was Secretary of Foreign Affairs (the office now called Secretary of State) and he was the first Chief Justice of the Supreme Court.

The Congress of the Confederation
The Articles of Confederation were in force from March 1, 1781, until the Constitution (ratified on June 21, 1788 by the nineth state, New Hampshire, giving the required 2/3 majority) went into effect on March 4, 1789. The Presidents leading this congress were
Samuel Huntington of Connecticut [Journals of the Continental Congress, 1774-1789, XIX, 223] served from March 2, 1781 to July 9, 1781, when he resigned for reasons of health.
Thoman McKean of Delaware was elected on July 10, 1781 to complete the term to November 4, 1781. He was in office when the British surrendered at Yorktown. He strongly supported the Constitution. He was governor of Pennsylvania for three stormy terms during which he appointed only Republicans to office.
John Hanson of maryland was elected on January 5, 1782, and served the first full one-year term under the official Articles from November 5, 1781, to November 3, 1782. Two of his sons were killed in action with the Continental Army. He was an ardent anti-Federalist, opposing the proposed Constitution until his untimely death in 1783.
Elias Boudinot of New Jersey served a full term from November 4, 1782, to November 2, 1783.
Thomas Mifflin of Pennsylvania served as President from November 3, 1783 to November 29, 1784. As President he signed the treaty (with Great Britain) that formally ended the war.
Richard Henry Lee of Virginia served as President from November 30, 1784 to November 22, 1785. He had written the resolution approved July 2, 1776, "that these United Colonies are, and of right ought to be, free and independent states". He later wrote the Northwest Ordinances, which provided for the formation of new states from the Northwest Territory
John Hancock of Massachusetts was the President (again) from November 23, 1785, to June 5, 1786. He was unable to complete his full term in office.
Nathanial Gorham of Massachusetts completed Hancock's term from June 6, 1786, to February 1, 1787. This was several months longer than a year because the date of inauguration was changed). During this time Congress considered inviting a member of European royalty to form a constitutional monarchy in America.
Arthur St. Clair of Pennsylvania served as President from February 2, 1787 to January 21, 1788. He was an anti-Federalist, fearing that the proposed Constitution would allow the intrusion of government into every aspect of life.
Cyrus Griffin of Virginia served as the nation's chief executive from January 22, 1788 until George Washington's inauguration on April 30, 1789. Although he started out an anti-Federalist, he eventually accepted the new Constitution with the promise of the Bill of Rights as protection against the formation of a constitutional monarchy.