Thomas Viaduct, Relay House, Viaduct Hotel - The War Between the States turned the Relay area into a major military base with camps, artillery emplacements, and two major forts located on both sides of the Patapsco River guarding the Thomas Viaduct. The Viaduct Hotel once located by the white monument and Viaduct is gone but the Relay House hotel and train station is still there. The Relay House is where Robert E. Lee, Jeb Stuart, and the Marines passed through to suppress the John Brown insurrection. Several US presidents also visited including Lincoln.