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 .

[254] and official orders for its discontinuance. My further instructions were, that in case any of the visitors of Mrs. Greenhow should attempt to pass the lines of our troops, they should be arrested at once, and a rigorous search of their persons instituted, in order that nothing should be allowed to pass through without a thorough examination by the Secretary of War or Mr. Scott.

After the departure of the Secretary I took with me two of my men, and proceeded to the vicinity of the residence of Mrs. Greenhow. I was then quite a stranger in Washington, and localities were not as familiar to me as they afterward became, and I therefore preferred to reconnoiter by daylight, to depending upon a survey after nightfall.

The entire day had been dark, gloomy and threatening; clouds had been gathering in the heavens, and everything indicated the imminence of a severe storm. As I left my headquarters, a slight shower of rain was falling, which I knew was but the precursor of a storm more violent. On arriving at the designated locality I found everything to be as they had already been described to me. The inside shutters to the windows were closed, and no sign was apparent that the house was occupied, and after carefully noting the situation and the exposed condition of the premises, I left the two men within a convenient distance of the place, and returned for the additional aid which I thought might be needed. Selecting three of my most discreet