Why did Nathan Bedford Forrest demand the surrender of Fort Pillow?

Confederate Maj. Gen. Nathan Bedford Forrest demanded the surrender of Fort Pillow on April 12, 1864, as part of a broader military expedition into West Tennessee and Kentucky. During this campaign, Forrest sought to secure recruits, provisions, and mounts to address severe Confederate supply shortages, as well as to disrupt the preparations of Union Gen. William T. Sherman for his upcoming drive on Atlanta.1

Forrest, who had earned a reputation for being a temperamental commander known for issuing "surrender or die" ultimatums, surrounded the fort with his cavalrymen and subjected the garrison to constant artillery and rifle fire throughout the day. After hours of combat, he issued the demand for surrender at 3:30 pm. When the Union commander requested a cease-fire, Forrest grew suspicious that the time was being used to reinforce the garrison, leading him to terminate the negotiations and order his men to storm the fort.1