The area that now contains almost all of Arlington County was ceded to the new United States federal government by Virginia, along with most of what is now the city of Alexandria. With the passage of the Residence Act in 1790, Congress approved a new permanent capital to be located on the Potomac River, the exact area to be selected by U.S. President George Washington. The Residence Act originally only allowed the President to select a location within Maryland as far east as what is now the Anacostia River. However, President Washington shifted the federal territory's borders to the southeast in order to include the existing town of Alexandria at the District's southern tip.