President Lincoln lay ill after returning from delivering his historic speech at Gettysburg in mid-November 1863.
He was confined with varioloid, a mild form of smallpox. He joked with a visitor that the president always had a crowd of people asking him to give them something, and now he has something he can give them all.
He had designated the last Thursday of that month as the nation’s first official Thanksgiving, but he was too ill to enjoy it.
Source: Freedom Rising: Washington in the Civil War by Ernest B. Furgurson