By 1860 Baltimore was the largest industrial city in the South and the third largest city in the United States. Three major railroads and an endless stream of sailing vessels traded its commerce over a major part of the country and the world. At the same time a flood of Irish and German immigrants during the 1850s combined with the industrialization of the city to undermine the institution of slavery. Baltimore City had a strong Southern social order with many ties to Virginia and the deep South. Yet, only in Southern Maryland did the plantation system of the colonial period remain unchanged. Its population of 200,000 in 1860 contained 50,000 free blacks, the largest anywhere in the nation. Those still enslaved in the city were primarily house servants or in some way specially trained. In 1864 hundreds of Free Black males would join their still enslaved brothers to form six full regiments of US Colored Troops which were recruited in Baltimore City and on both shores of the Chesapeake Bay. When the war came in 1861, Maryland would be on the fault line of secession no matter which government its citizens voted to support. Baltimore City with its transportation and industrial assets would be a valuable prize to whichever side could control her. It is no wonder that all but the most heated firebrands waited until every avenue of compromise was exhausted before choosing sides in a war in which they had much to lose and very little to gain. Never before have the people, places and events that occurred in this great city between the years 1860 and 1865 been presented in one continuous story. The authors now proudly tell that story in Baltimore During the Civil War. - Introduction.