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 .

[566] of the Potomac, that had those in power in Washington been less concerned for their own safety, and trusted more to the skill and sagacity of the general in the field to direct its movements, the history of that army would have been widely different from what it is. The campaign of the Peninsula terminated disastrously to the Union arms, and it was mainly due to this real or assumed fear of the authorities for the safety of Washington.

It is not presuming too much to say, that McClellan knew far better than those at Washington the movements and intentions of the enemy, and that he was apprised of them sooner; but it is equally true that a certain element in the Cabinet was unfriendly to the secret service branch of the army, and, with characteristic stubbornness, placed but little reliance upon the information obtained from this source.

For instance, General Halleck was of the opinion, on the evening of the day before Antietam, that Lee's whole force had crossed the river, and so telegraphed McClellan, when the fact was that the rebel army was actually in our front, and ready for the battle that so speedily followed.

Still, the importance of moving with extreme caution was kept constantly in view, and the army was moved so that it extended from the railroad to the Potomac River, the extreme left flank resting on that stream.

On the twelfth of September, a portion of the