Maryland was trembling in the balance between Union and disunion. A determined disunionist minority was working with might and main to drag the State into secession. Baltimore was white-hot with southern zeal, determined that the Bay State troops should never reach Washington through that metropolis. Eight of the cars containing the soldiers were drawn safely across the city. The next was assailed by a hooting mob, and the windows smashed in by bricks and paving stones. Some of the soldiers were wounded by pistol shots, and a scattering fire was returned. Sand, stones, anchors, and other obstructions were heaped upon the track. The remaining four companies therefore left the cars and started to march. They soon met the mob, flying a secession flag. A melee ensued. The troops moved double-quick toward the Washington depot, surrounded by a seething mass of infuriated secessionists filling the air with their brick-bats and stones, while bullets whizzed from sidewalks and windows. The troops returned the fire, and several in the crowd fell. The chief of police with fifty officers appeared on the scene, who, by presenting cocked revolvers, held the rioters in check for a while, till the distressed troops could join their comrades. Baltimore was in the hands of this secessionist band for the rest of the day. The bridges north of that city were also burned, so that no more troops could reach Washington by this route. [Illustration: Waterfront; ships and buildings.] Scene of the First Bloodshed, at Baltimore. Meanwhile the capital city was in great peril, devotees of the South being each moment expected to make an attack upon it. Only fifteen companies of local militia and six of regulars were present at inauguration time, stationed by General Scott at critical points in the city. Pickets were posted continually on roads and bridges outside. Four hundred Pennsylvania troops happily arrived on April 18th, and the next day came the Sixth Massachusetts. But the city was not yet secure. There were reports that large bodies of men were gathering in Maryland and Virginia for a descent upon it. Washington was put in a state of siege, the public buildings barricaded and provided with sentinels. The Government seized the Potomac steamers and also all the flour within reach. Business ceased. Alarmed by rumors of a military impressment, hundreds of government clerks, besides officers in the army and navy, came out in their true colors and fled south. Enemies at Baltimore had cut off telegraphic communication between Washington and the North. Reports came that re-enforcements were on the way, but day followed day without witnessing their arrival. The President and all Unionists were in an agony of suspense. [Illustration: Map of Pennsylvania, New Jersey, Maryland and Virginia.] The Routes of Approach to Washington. Russell & Struthers, Eng's, N. York.