When Congress arrived in the new capital, they passed the Organic Act of 1801 to officially organize the District of Columbia and placed the entire federal territory, including the cities of Washington, Georgetown, and Alexandria, under the exclusive control of Congress. Further, the territory within the District was organized into two counties: the County of Washington to the east of the Potomac and the County of Alexandria to the west. It included almost all of the present Arlington County, plus part of what is now the independent city of Alexandria. This Act formally established the borders of the area that would eventually become Arlington but the citizens located in the District were no longer considered residents of Maryland or Virginia, thus ending their representation in Congress.