Yes, Abraham Lincoln was sick when he died.
Lincoln's Illness
Lincoln suffered from a severe case of acute malaria in the spring of 1865. He had been experiencing symptoms such as fatigue, chills, and fever for several weeks leading up to his assassination.
The Assassination
On April 14, 1865, Lincoln was shot by John Wilkes Booth at Ford's Theatre in Washington, D.C. He died the following morning.
The Impact of Lincoln's Illness
While the assassination was the immediate cause of Lincoln's death, his weakened state due to malaria likely contributed to the severity of his injuries and the speed of his demise.
In Conclusion: Abraham Lincoln was suffering from malaria when he was assassinated, and his weakened condition may have played a role in his death.