In terms of sources, only those which documented the decision-making process of the powerful mattered: Lee’s memoranda and Forrest’s letters, yes, but not plantation record books or ordinary soldier’s diaries or interviews with people who knew Sojourner Truth. And people who left no written documents simply did not exist in this sort of historical account, except in the aggregate, as in “Napoleon led twenty thousand men into the campaign.”. In terms of historical events, only those which directly effected the course of a war or an election counted for this kind of history: battles mattered, but harvests did not; treaties mattered, but escapes from slavery did not; Presidential elections mattered, but mill-workers’ strikes did not. And so on. And it was always event rather than process which caught the attention of this sort of historian: slow change over time in religious conviction or political philosophy means nothing to Foote’s account of the Civil War (at least in this interview) which is why he can’t imagine himself fighting to end slavery. This is how a historian could learn every detail of a military action, of many military actions, and still understand nothing that matters.