Known sourcecanonical
"No other terms than unconditional and immediate surrender. I propose to move immediately upon your works."
Ulysses S. Grant / To Gen. S. B. Buckner, Fort Donelson, Feb. 16, 1862.
To Gen. S. B. Buckner, Fort Donelson, Feb. 16, 1862.
Bartlett's Familiar Quotations, 9th ed. (Little, Brown, 1905), public domain