"According to Confederate ideology, blacks liked slavery; nevertheless, to avert revolts and runaways, the Confederate states passed the 'twenty nigger law', exempting from military conscription one white man as overseer for every twenty slaves. Throughout the war, Confederates withheld as much as a third of their fighting forces from the front lines and scattered them throughout areas with large slave populations to prevent slave uprisings. When the United States allowed African Americans to enlist, Confederates were forced by their ideology to assert that it would not work; blacks would hardly fight like white men. The undeniable bravery of the 54th Massachusetts and other black regiments disproved the idea of black inferiority. Then came the incongruity of truly beastly behavior by southern whites towards captured black soldiers, such as the infamous Fort Pillow massacre by troops under Nathan Bedford Forrest, who crucified black prisoners on tent frames and then burned them alive, all in the name of preserving white civilization."