President Abraham Lincoln was a father who absolutely doted-on his boys. They helped to ground him amidst all of the turmoil which surrounded Lincoln's life as a war-time Commander-in-Chief.
For Lincoln, the war years were worse than they were for other Presidents since, during his tenure in the White House, America's war was with herself.
William Wallace Lincoln—whom everyone called "Willie"—was 11 years old on the 20th of February, 1862. Because his father was America's 16th president, Willie and his family had moved into the White House—in Washington, D.C.—the previous March. (At that time, U.S. presidents took the oath of office in March.)
Willie raised a boys' batallion of "troops," consisting of himself and his friends from school. Sometimes he, and his troops, invaded the President's official cabinet meetings. Lincoln never minded those interruptions.
Willie wasn't just interested in raising a batallion, however. He was a studious child who also wrote verse and memorized railroad timetables. His father delighted in spending time with both Willie and Tad.
Then ... in February of 1862, when there was no end in sight for America's civil war ... disaster visited the White House.
Both Tad and Willie were ill, likely with typhus (which is sometimes called "bilious fever"). Tad recovered; Willie did not. He died on February 20th, 1862 (eight days after his father's birthday).
Both of his parents were inconsolable. For about three months Mary, Willie's mother, vacillated between periods of loud weeping and utter silence.
The President, who was utterly aggrieved at Willie's death, had little time to mourn him because of his war-time responsibilities. Before long, he was back to working eighteen-hour days.
Three years later—after the President was assassinated and his body was being transported aboard a funeral train to Springfield, Illinois—something else was on that train. It was Willie’s coffin which had been removed, from a temporary resting place, to travel with the President’s remains.
Willie’s body was reinterred, near his Papa’s final resting place. Both father and son are buried at Oak Ridge Cemetery in Springfield, Illinois.
This clip, from a PBS documentary, provides more details on Willie's death and its impact on the Lincoln family.
Clip from a PBS documentary online, via YouTube. Copyright, PBS, all rights reserved. Clip provided here as fair use for educational purposes.