Short answers, pulled from the story.
The Natchez attacked Fort Saint Pierre on the 29th of November 1729. They murdered several hundred settlers including Jesuit missionary Paul Du Poisson and took women and children as captives.
Confederate General John C. Pemberton surrendered to Union forces on the 4th of July 1863 after a 47-day siege. This event marked the turning point of the Civil War in favor of the Union alongside the defeat of General Robert E. Lee at Gettysburg.
White men disrupted a black Republican meeting celebrating Peter Crosby's election on the 7th of December 1874 and ran him out of town. Armed white mobs subsequently killed hundreds of blacks in Claiborne County during the following days.
A Mississippi River flood cut off the large meander next to Vicksburg through De Soto Point in 1876, changing the river course away from the city. The area became an oxbow lake that effectively isolated the city from accessing the Mississippi riverfront until the Yazoo Diversion Canal opened in 1903.
Activists in the Vicksburg Movement became prominent during the 1960s following decades of exclusion from the political system. As of the 2020 census there were 21,573 people with 67.21% identifying as African American.