Allan Pinkerton, The spy in the rebellion; being a true history of the spy system of the United States Army during the late rebellion, revealing many secrets of the war hitherto not made public, compiled from official reports prepared for President Lincoln , General McClellan and the Provost-Marshal-General .

[294] alarm, at the unexpected revelations which were made. It became evident to him that these conspirators had by some means succeeded in placing themselves in direct communication with the Confederate leaders, and that a gigantic plot was now in preparation to make a united and irresistible movement against Washington. Nearly ten thousand Baltimoreans, it was alleged, were prepared to rise in arms at a moment's notice, and join the rebel army, whenever such a movement might seem feasible. It appeared, also, that the Baltimoreans were not alone in this plot against the government, but that branches of their organization existed in a number of the outlying towns, and that the secessionists of the entire State were working harmoniously together for the accomplishment of one great purpose. There was no lack of arms, for these had already been secured, but their place of concealment was known only to a few and they were not to be brought to light until they should be needed.

The main portion of the plot seemed to be well matured, and was most perfect in its details. The arrival of the rebel army in Maryland was expected in a very short time, as they had the promises of the Southern commanders themselves that they would soon cross the Potomac. Their coming was to be the signal for a simultaneous uprising of all the secessionists in the Western and Southern portions of the State, who were to unite in a movement that