Walney witnessed extensive troop movement during the American Civil War due to its proximity to Washington D.C. In the winter of 1861-1862, over 40,000 troops camped in the Centreville area, cutting down local trees for firewood, fortifications and shelter, damaging woods, fields, and gardens.
 During this winter, Walney was used to house a few of the sick soldiers in the area to be cared for by the Machen women.
  
In August 1862, directly following the Battle of Second Manassas, Walney was right in the path of the Union retreat.
 Union soldiers passed through Walney and stole oxen, horses, food and supplies.
They also plundered the stone house and tried to break into the frame house in which Lewis Machen was lying ill.
Union soldiers were stopped from entering by Caroline Machen, who stood, barricading the door, until a passing Union officer ordered the men away and stopped the assault.
 The next day, on September 1st, 1862, the Battle of Ox Hill occurred on a portion of the property in the Machen’s cornfield.
 
Despite the troop movements and action seen during the war, Walney survived with less property loss than many of the neighboring farms.
However, the war had taken a toll on the Machens.
Lewis Machen died in 1863, shortly after leaving Walney to take refuge in Baltimore with Arthur.
Caroline and daughter Emmeline would remain in Baltimore for the rest of their lives, returning to Walney only for family visits.
James returned from service with the Confederate Army to try to rebuild his family's farm despite the losses of war.
Walney witnessed extensive troop movement during the American Civil War due to its proximity to Washington D.C. In the winter of 1861-1862, over 40,000 troops camped in the Centreville area, cutting down local trees for firewood, fortifications and shelter, damaging woods, fields, and gardens.  During this winter, Walney was used to house a few of the sick soldiers in the area to be cared for by the Machen women.   
In August 1862, directly following the Battle of Second Manassas, Walney was right in the path of the Union retreat.  Union soldiers passed through Walney and stole oxen, horses, food and supplies. They also plundered the stone house and tried to break into the frame house in which Lewis Machen was lying ill. Union soldiers were stopped from entering by Caroline Machen, who stood, barricading the door, until a passing Union officer ordered the men away and stopped the assault.  The next day, on September 1st, 1862, the Battle of Ox Hill occurred on a portion of the property in the Machen’s cornfield.  
Despite the troop movements and action seen during the war, Walney survived with less property loss than many of the neighboring farms. However, the war had taken a toll on the Machens. Lewis Machen died in 1863, shortly after leaving Walney to take refuge in Baltimore with Arthur. Caroline and daughter Emmeline would remain in Baltimore for the rest of their lives, returning to Walney only for family visits. James returned from service with the Confederate Army to try to rebuild his family's farm despite the losses of war.
Ellanor C. Lawrence Park