According to this letter, what is a key difference between the attack on President Lincoln and Secretary Seward?

The author thinks that Seward will die from his knife wounds, but Lincoln will survive his gunshot wounds.

Lincoln was shot while in his house and Seward was shot while at a theater.

Seward was shot in the back of the head and Lincoln was stabbed repeatedly.

The author thinks that Lincoln will die from his gunshot wounds, but thinks that Seward will survive his knife wounds.