A、In 1791. B、In 1799. C、In 1774. D、In 1776. B细节题。短文结尾处明确提到，乔治·华盛顿(George Washington)死于1799年，故答案为B)。

During the American War of Independence(1775-1783)and[22]in the first days after the founding of the nation, there was a dispute between the northern and southern states as to where the capital of the new country should be located.
    For most of the Revolutionary War period, the rebels’ capital was[23]Philadelphia. The First Continental Congress of 1774 was held there, so was the second one in 1776, the one which proclaimed The Declaration of Independence; and in 1787 the Federal Constitution was adopted there, too. Larger New York served as the capital for a while. From 1790 to 1800, however, Philadelphia was once more the capital.
    To solve the problem,[24]George Washington, the first President of the United States, personally selected an area on the northeastern shore of the Potomac River between the states of Maryland and Virginia as the new capital. This was as early as 1791. He appointed Pierre L. Enfant, a French engineer who had fought in the Revolution, to prepare a plan for the new city.[25]George Washington died in 1799, so it was John Adams, the second President, who moved the capital to the new seat, which was yet to be completed. To commemorate George Washington, the new capital was named after him.
22. What was the dispute between the northern and southern states just after the U.S. was founded, according to the passage?
23. Where was the First Continental Congress held?
24. What can we learn about the capital of the U.S.?
25. When did George Washington die?