▁in ▁reality , ▁thought ▁to ▁be ▁the ▁work ▁of ▁his ▁assist ants . ▁Br ady ▁was ▁critic ized ▁for ▁failing ▁to ▁document ▁the ▁work , ▁though ▁it ▁is ▁unclear ▁whether ▁it ▁was ▁intent ional ▁or ▁due ▁simply ▁to ▁a ▁lack ▁of ▁incl ination ▁to ▁document ▁the ▁photograph er ▁of ▁a ▁specific ▁image . ▁Because ▁so ▁much ▁of ▁Br ady ' s ▁phot ography ▁is ▁missing ▁information , ▁it ▁is ▁difficult ▁to ▁know ▁not ▁only ▁who ▁took ▁the ▁picture , ▁but ▁also ▁exactly ▁when ▁or ▁where ▁it ▁was ▁taken . ▁ ▁In ▁October ▁ 1 8 6 2 ▁Br ady ▁opened ▁an ▁exhibition ▁of ▁photograph s ▁from ▁the ▁Battle ▁of ▁Anti et am ▁in ▁his ▁New ▁York ▁gallery , ▁titled ▁The ▁Dead ▁of ▁Anti et am . ▁Many ▁images ▁in ▁this ▁presentation ▁were ▁graph ic ▁photograph s ▁of ▁corps es , ▁a ▁presentation ▁new ▁to ▁America . ▁This ▁was ▁the ▁first ▁time ▁that ▁many ▁Americans ▁saw ▁the ▁real ities ▁of ▁war ▁in ▁photograph s , ▁as ▁distinct ▁from ▁previous ▁" art ists ' ▁impress ions ". ▁ ▁Mat hew ▁Br ady , ▁through ▁his ▁many ▁paid ▁assist ants , ▁took ▁thousands ▁of ▁photos ▁of ▁American ▁Civil ▁War ▁scenes . ▁Much ▁of ▁the ▁popular ▁understanding ▁of ▁the ▁Civil ▁War ▁comes ▁from ▁these ▁photos . ▁There ▁are ▁thousands ▁of ▁photos ▁in ▁the ▁US ▁National ▁Archives ▁and ▁the ▁Library ▁of ▁Congress ▁taken ▁by ▁Br ady ▁and ▁his ▁associ ates , ▁Alexander ▁Gard ner , ▁George ▁Bar n ard ▁and ▁Tim othy ▁O ' S ull ivan .