Both armies arrived with roughly 35,000 troops, yet each committed only about 18,000. The Union also had 14,000 to 18,000 troops nearby that never joined the battle. Union losses totaled 2,708: 481 killed, about 1,000 wounded, and about 1,200 missing. Confederate losses included 387 killed, nearly 1,600 wounded, and 13 missing. The victory made the reputations of Beauregard, Jackson, and Johnston while damaging those of McDowell and Patterson.
Notable Point · 3:39-5:36
The armies Bull Run actually used
Both sides brought roughly 35,000 troops but engaged about 18,000 each, while casualties and command reputations reveal the cost of committing unready armies piecemeal.