Willie Lincoln’s death had a profound effect on President Lincoln, but his persecution of the war was not affected seriously.
Willie died of typhoid fever from contaminated drinking water. The entire family fell into a dismal depression for months. Tad, his younger brother, cried for hours at a time while his mother began to become obsessed with the occult and attended séances in order to contact her boy.
Lincoln was also deeply affected. He generated no official correspondence for fours days while he mourned. This brief interruption didn’t affect the war effort as other federal departments continued on despite the President’s absence.
John Hay, a secretary who worked closely with the President in the White House, wrote that Willie’s death did not keep the President from his duties for very long. He said the President "was profoundly moved by his death, though he gave no outward sign of his trouble, but kept about his work the same as ever. His bereaved heart seemed afterwards to pour out its fullness on his youngest child."