What if, through whatever course, the American Civil War is delayed until the 1880s or 1890s? What is the probability that one or more sides could adopt Prussian-style "needle guns"?
Further, as a broader question - how would a delayed Civil War effect global war strategy, seeing as tactics developed in OTL ACW were utilized in WWI?
EDIT - Oops, I meant to say "American Civil War with Needle Guns"!