Front Royal was a military target in the Civil War because it straddled the Manassas Gap Railroad and the northern entrance to the Page Valley
Source: Frank Leslie's Illustrated History of the Civil War, Front Royal Manassas Gap Railroad - Blue Ridge Mountains in the Distance - the Federal Army Entering the Town (p.144)
Warren County was named for Major General Joseph Warren. He was an activist in Boston who opposed the Intolerable Acts passed by the British Parliament. When the Regular troops were preparing to march out of Boston to seize military supplies stockpiled in the countryside, Dr. Warren recruited Paul Revere and William Dawes to provide an alert. Their midnight ride started once two lanterns in the tower of the Old North Church made clear that the soldiers were leaving Boston by sea on April 19, 1775 to reach Charlestown and start the march to Concord.
Dr. Warren was killed in the Battle of Bunker Hill. When the Virginia General Assembly created a new copunty on March 9, 1836, the name was chosen to honor Dr. Warren.1