 McClellan's subsequent campaigns were strongly influenced by the overblown enemy strength estimates of his secret service chief, detective Allan Pinkerton, but in August 1861, these estimates were entirely McClellan's own.The result was a level of extreme caution that sapped the initiative of McClellan's army and dismayed the government.Historian and biographer Stephen W. Sears observed that McClellan's actions would have been "essentially sound" for a commander who was as outnumbered as McClellan thought he was, but McClellan in fact rarely had less than a two-to-one advantage over the armies that opposed him in 1861 and 1862.