McCausland fought as a cavalry brigade commander during the Valley Campaigns of 1864, under Lieutenant General Jubal A. Early, using his 2,800 men in various configurations to raid into Maryland (often extorting large sums of money from towns by threatening to burn them) and Pennsylvania. Under Early's orders, on July 30, 1864, McCausland burned the town of Chambersburg, Pennsylvania, after it failed to pay a $100,000 extortion demand, justifying it as retaliation for the private property destroyed during Hunter's Shenandoah Valley campaign. In fact, Early's orders left little room for compromise or negotiation, and bankers had removed most of the money from Chambersburg days earlier. Plus despite Union General Darius Couch's early morning telegrams about the oncoming raiders, General William Averell's cavalry did not arrive from nearby Greencastle until after 2p.m., only to find still-burning ruins, displaced civilians and a trail of miscellaneous merchandise looted, then dropped by McCausland's departing raiders. The Union army relentlessly pursued McCausland's cavalry, ambushing and routing them at the Battle of Moorefield on August 8th.