On November 6, 1860, Abraham Lincoln became the fluky victor in a tight race for president. The country was bitterly at odds; Southern extremists were moving ever closer to destroying the Union, with one state after another seceding and Lincoln powerless to stop them. Slavery fueled the conflict, but somehow the passions of North and South came to focus on a lonely federal fortress in Charleston Harbor: Fort Sumter. Master storyteller Erik Larson...

The business triumphs of Bill Gates are widely known: the twenty-year-old who dropped out of Harvard to start a software company that became an industry giant and changed the way the world works and lives; the billionaire many times over who turned his attention to philanthropic pursuits to address climate change, global health, and U.S. education. Source Code is not about Microsoft or the Gates Foundation or the future of technology. It's the human,...