In June 1864, Confederate Gen. Robert E. Lee sent Gen. Jubal A. Early’s corps from the Richmond battlefields to the Shenandoah Valley to counter Union Gen. David Hunter’s army. After driving Hunter into West Virginia, Early invaded Maryland to attack Washington D.C., draw Union troops from Richmond, and release Confederate prisoners held at Point Lookout. On July 9, Early ordered Gen. Bradley T. Johnson’s cavalry brigade eastward to free the prisoners, and Johnson sent Maj. Harry Gilmor’s regiment to raid the Baltimore area. On July 10, 1864, Gilmor surprised his parents with a brief visit to Glen Ellen, his boyhood home in the Dulaney Valley just southwest of here, while raiding Baltimore and Harford counties as part of Early’s Maryland invasion. Johnson’s brigade included Gilmor’s command, the 2nd Maryland Cavalry Battalion, which had been sent to cut communications and transportation lines. Glen Ellen, whose main house was known as The Castle, reflected Gilmor’s Scottish ancestry. His father, Robert Gilmor III, had visited Scotland as a young man, stayed at Abbotsford, the estate of Sir Walter Scott, and then hired architect Andrew Jackson Davis to design a dwelling around 1832 modeled on Abbotsford. He named the property Glen Ellen after his wife, Ellen Ward Gilmor, and they had nine sons and two daughters. The house contained a circular ballroom with large bay windows, numerous bedrooms, an extensive library, ornate moldings, and elaborate woodwork. It remained in the family until 1883, when construction of Loch Raven Reservoir ultimately rendered it uninhabitable; parts were removed, and the remainder fell into ruin.