On this day in 1863, Union gunboats fired 443 mortar shells into Vicksburg in a single day.
But that number alone doesn't tell you what it was actually like to be inside the city.
By this point, over 500 caves had been dug into the yellow clay hillsides of Vicksburg. Families lived underground for weeks. Some caves were carpeted. Some had furniture. Enslaved people charged $30 to $50 per cave to dig them out for families who couldn't do it themselves.
The civilians got eerily good at identifying incoming fire by sound alone. Parrott shells made a whistling shriek and were the most feared. Mortar rounds, though, made a slow arc through the sky you could actually track, almost lazy, more like "fireworks." People would step outside, watch one rise, calculate its trajectory, and go back underground.
Over the full 39-day siege, roughly 22,000 shells landed in the city. Every pane of glass in Vicksburg was shattered. Not most. Every single one.
Food ran out first. Then dignity. Citizens ate mules. Then rats. Then their pets.
"We are utterly cut off from the world, surrounded by a circle of fire," wrote civilian Dora Miller in her diary.
The guns never broke the city. Grant's army never stormed it. Vicksburg surrendered on July 4, 1863, because the people inside were starving to death.
30,000 Confederate soldiers laid down their arms. Grant, rather than humiliating them, let them walk home on parole.
The most devastating siege on American soil, and most people couldn't name a single detail from it.