Editing Battle of Cool Spring (section)

==Background==
After the [[Battle of Fort Stevens]] on July 11, a [[Union Army|Union]] column, consisting of the [[VI Corps (Union Army)|VI Corps]] and elements of the [[XIX Corps (Union Army)|XIX Corps]] under [[Major general (United States)|Maj. Gen.]] [[Horatio Wright]], pursued [[Lieutenant general (United States)|Lt. Gen.]] [[Jubal Early]]'s [[Army of the Valley]] northwestward as it withdrew from the environs of [[Washington, D.C.]], through [[Loudoun County, Virginia]]. On July 15, Wright's force was joined by elements of [[Brigadier general (United States)|Brig. Gen.]] [[George Crook]]'s command, which had accompanied Maj. Gen. [[David Hunter]] during his retreat through [[West Virginia]] following the [[Battle of Lynchburg]] on June 18.

After two brief engagements in Loudoun County at [[Heaton's Crossroads]] (present day [[Purcellville, Virginia|Purcellville]]) and Woodgrove on July 16, Early's main force crossed west over the [[Blue Ridge Mountains]] at [[Snickers Gap]] and established themselves around [[Berryville, Virginia|Berryville]]. To cover his rear, Early left substantial rearguard forces at main river crossings of the [[Shenandoah River]]. On July 17, the Union [[cavalry]] passed westward through Snicker's Gap and unsuccessfully attempted to force passage of the river at Castleman's Ferry (Snicker's Ford).

The following day, Union Generals Crook and Wright arrived at Snicker's Gap and determined to attack what they mistakenly thought was a light picket line of Confederates along the river, left to cover Early's retreat up the Valley. Instead of allowing his cavalry to cross the river and reconnoiter the Confederate positions to confirm this assumption, he dispatched them to [[Ashby's Gap]] to attack Early's supply train, which was traveling to the south of Early's main army. Wright then developed a plan where a small Federal force would cross the river northward, downstream from the main crossing at Castleman's Ferry and flank the Confederate position. Gen. Crook assigned Col. [[Joseph Thoburn]] to this task.