As a major crossroads, Frederick, like Winchester, Virginia, and Martinsburg, West Virginia, saw considerable action during the American Civil War. Slaves also escaped from or through Frederick (since Maryland was still a "slave state" although an unseceded border state) to join the Union forces, work against the Confederacy and seek freedom. During the Maryland campaigns, both Union and Confederate troops marched through the city. Frederick also hosted several hospitals to nurse the wounded from those battles, as is related in the National Museum of Civil War Medicine on East Patrick Street.