Not as well known or remembered is the crucial role played by the City of Baltimore and Fort McHenry in determining the outcome of the war. Baltimore's strategic location as a port and major transportation center was realized by the British in 1814. Capture of the location during the War of 1812 would have given the British key control of the American east coast. In the intervening 50 years, Baltimore's importance as a trade center continued to grow. Yankees on southern soil were met by an angry mob bent on supporting the States' rights to secede.
Shots rang out and the first casualties of our Civil War fell.
President Lincoln recognized the strategic importance of Baltimore and its protecting fort. Fearing a vote in the Maryland legislature to join the rebel southern states, Lincoln suspended the writ of Habeas Corpus, the constitutional right to have one's case heard, and in May 1861, imprisoned key Maryland legislators in Fort McHenry. The Supreme Court responded with its decision in the case of Merryman v. United States, finding the President in violation of the Constitution and issuing a writ. By the end of the war nearly 2,000 civilians had been imprisoned at Fort McHenry. Congress finally gave the President authority to suspend the writ.