John G. Nicolay, The Outbreak of Rebellion

Coming to Washington under the favorable acquaintanceship and estimate of General Scott, and with the prestige of his recent success in West Virginia, McClellan's arrival was hailed by officials and citizens with something more than ordinary warmth and satisfaction. This good opinion was greatly augmented by the General's own personal conduct. He exhibited at once a promising energy and industry in repairing the shattered army organization; cleared Washington City of stragglers; established a more perfect military discipline than had hitherto been maintained; displayed great tact in his first intercourse with both junior and senior officers; was free, affable, kind, patient, and attentive to all; manifested great talent and unceasing watchfulness in the details of military administration; and being young, vigilant, cheerful, intelligent, and apparently possessed of great professional skill, he reaped, almost at a single harvest, a well-nigh universal popularity.

It is in its political aspects that Bull Run becomes a great historical landmark. To say that the hope and enthusiasm of the North received a painful shock of humiliation and disappointment, is to use but a mild description of the popular feeling. This first experience of defeat-or recognition of even the possibility of defeat — was inexpressibly bitter. Stifling the sharp sorrow, however, the great public of the Free States sent up its prompt and united demand that the contest should be continued and the disgrace wiped out Impatience and over eagerness were chastened and repressed; and the North reconciled itself to the painful prospect of a tedious civil war all the more readily because of the necessity