 Jackson was then killed by invading Federal soldiers of the 11th New York, on his own property, in defense of his home.Throughout the remainder of the war, Alexandria would lean strongly towards the Confederate government, necessitating continued occupation by a Union garrison.Over the seven weeks that followed the occupation of northern Virginia, forts were constructed along the banks of the Potomac River and at the approaches to each of the three major bridges (Chain Bridge, Long Bridge, and Aqueduct Bridge) connecting Virginia to Washington and Georgetown.