At 7:22 am on this day in 1865, Abraham Lincoln died. The previous evening, during the third act of a performance of Our American Cousin at Ford’s Theater, John Wilkes Booth, enraged by the speech discussed here, had shot Lincoln in the head. A single bullet had entered through the rear of Lincoln’s skull and lodged behind his right eye. The wound had bled very little. As word of the assassination attempt spread throughout Washington, Cabinet members, Congressmen, and other officials had descended upon Ford’s Theater, where surgeons struggled to keep Lincoln alive. They failed, and the nation mourned. It mourns still.

I’m agnostic about counterfactuals. Sometimes, they seem to offer a way to test theories. At others, they strike me as little more than a conceit or a sideshow, a diversion my students find endlessly fascinating, and therefore an annoyance in the context of my courses. But when it comes to Lincoln, I can’t help but consider the counterfactual: what if he had lived? How different would Reconstruction have been with Lincoln watching over its progress? Might there have been land reform in the South? Or would Lincoln have been more lenient even than Johnson in service of reconciliation? Beyond that, how different would the Republican Party’s history have been had Lincoln lived into his dotage, an elder statesmen protecting his own legacy? We have no answers for these and a host of other questions [insert yours below]. But each of these queries fascinates me. I fight my inner romantic when I consider the implications of Lincoln’s death and what the nation lost on this day in 1865.

Eric, whose pet counterfactual revolves around Lincoln living and Seward dying — with the martyred Seward looking over his shoulder, Lincoln would have had added moral authority and motivation to remake the South — turned me on to Niall Ferguson’s edited volume on counterfactuals. Ferguson’s introduction is wide-ranging: from Peggy Sue Got Married and Back to the Future to Michael Oakeshott and E.H. Carr to Augustine and John Calvin to Newton and Descartes to Hegel and Kant to Marx and Mill with stops along the way. As he skips across discursive time and space, Ferguson responds to E.P. Thompson’s contention that counterfactuals are “Geschichtswissenschlopff, unhistorical shit,” arguing that respect for contingency and chaos demand that we engage with counterfactuals. “Virtual history,” in this view, “is a necessary antidote for determinism.” That seems fair enough. But the book lacks a chapter on Lincoln, or the Civil War — a font of counterfactuals — more broadly. So it’s left to us to answer the simple question: what if?