Imagine him in the last week of his life, 150 years ago this month. Shuffling, clothes hanging loosely on the 6-foot-4-inch frame, that tinny voice, a face much older than someone of 56. “I am a tired man,” he said. “Sometimes I think I am the tiredest man on earth.”

Springtime in Washington, lilacs starting to flower. The Capitol Dome finally free of its scaffolding. His month began in triumph against the largest slaveholding nation on earth. Richmond fell and was set afire by its retreating residents. On April 4, Abraham Lincoln, with his 12-year-old son, Tad — his birthday! — walked the smoldering shell of the rebel capital, walked a mile or so, pressed by a throng of liberated blacks, to sit as a conqueror in the seat of the Southern White House.

“No day ever dawns for the slave,” wrote a man who had once been owned by a fellow man. In Richmond, thereafter, all days had dawns.

On the dawn of his final day, April 14, Lincoln rises as usual at 7 a.m., breakfasts on coffee and an egg. He meets with his cabinet, confers with an ex-slave, lunches with the unpredictable Mary Todd. They have plans to attend “Our American Cousin.” In the box at Ford’s Theater that evening, a white supremacist fires a single shot from a Derringer. The bullet penetrates Lincoln’s brain and lodges just behind his right eye. The most significant casualty in a war that took more lives than any other in the nation’s history dies the next morning — the first president to be murdered.

Now think of the legacy on this anniversary of the American passion play. Think of free land for the landless, the transcontinental railroad, the seeding of what would grow into national parks, the granting of human rights to people who had none. ...