After [[Virginia]] ratified secession, Union troops crossed the Potomac and, under Brig. Gen. [[Irvin McDowell]], took up positions around Arlington. During the occupation the Union founded several military installations at and around the mansion. These are survived today by parks in the surrounding community as well as Fort Myer. <ref>http://www.arlingtoncemetery.org/historical_information/arlington_house.html</ref> | After [[Virginia]] ratified secession, Union troops crossed the Potomac and, under Brig. Gen. [[Irvin McDowell]], took up positions around Arlington. During the occupation the Union founded several military installations at and around the mansion. These are survived today by parks in the surrounding community as well as Fort Myer. <ref>http://www.arlingtoncemetery.org/historical_information/arlington_house.html</ref> |