Journalists have been making history. In big, fat volumes. It’s getting harder and harder these days to tell the difference between books of history and books of journalism. Dozens of current or former journalists – like David Halberstam, Anne Applebaum, David Maraniss, Melissa Fay Greene, Richard Kluger, Stanley Karnow, and Robert Caro – have been writing meaty books about events they may not...