On April 18, 1861, the day after Virginia seceded from the Union, Virginia militia seized the federal arsenal at Harpers Ferry, which was also an important work station on the B&O's main westward line. The following day, Confederate rioters in Baltimore attempted to prevent Pennsylvania volunteers from proceeding from the North Central Railway's Bolton station to the B&O's Mount Clare station, and Maryland's governor Hicks and Baltimore Mayor George W. Brown ordered 3 North Central and 2 Philadelphia, Wilmington and Baltimore Railroad (PW&B) bridges destroyed to prevent further federal troop movements through (and riots in) the city. Soon B&O president John Work Garrett received letters from Virginia's Governor John Letcher telling the B&O to pass no federal troops destined for any place in Virginia over the railroad, and threatening to confiscate the lines. Charles Town's mayor also wrote, threatening to cut the B&O's main line by destroying the long bridge over the Potomac River at Harpers Ferry, and Garrett also received anonymous threats. Thus he and others asked Secretary of War Cameron to protect the B&O as the national capitol's main westward link. Cameron instead warned Garrett that passage of any rebel troops over his line would be treason. The Secretary of War agreed to station troops to protect the North Central, the Pennsylvania Railroad,and even the PW&B, but flatly refused to help the B&O.