Original sentence: One theory about the Lincoln Assassination holds that the Dahlgren Papers' discovery instigated the chain of events ending in John Wilkes Booth's assassination of Abraham Lincoln the next year
Edited sentence: One conjecture about the motivation of John Wilkes Booth for the Lincoln Assassination was that depite assassination not being considered acceptable strategy at the time, Booth felt justified in retaliating in kind to the orders purportedly in the Dahlgren Papers