empt ed ▁those ▁whose ▁ancest ors ▁( grand f athers ) ▁had ▁the ▁right ▁to ▁vote ▁before ▁the ▁Civil ▁War , ▁or ▁as ▁of ▁a ▁particular ▁date , ▁from ▁such ▁requirements . ▁The ▁intent ▁and ▁effect ▁of ▁such ▁rules ▁was ▁to ▁prevent ▁poor ▁and ▁ill iter ate ▁African - American ▁former ▁slaves ▁and ▁their ▁descend ants ▁from ▁voting , ▁but ▁without ▁den ying ▁poor ▁and ▁ill iter ate ▁whites ▁the ▁right ▁to ▁vote . ▁Although ▁these ▁original ▁grand father ▁cla uses ▁were ▁eventually ▁ruled ▁un const itution al , ▁the ▁terms ▁grand father ▁clause ▁and ▁grand father ▁have ▁been ▁adapted ▁to ▁other ▁uses . ▁ ▁Origin ▁The ▁original ▁grand father ▁cla uses ▁were ▁contained ▁in ▁new ▁state ▁constitution s ▁and ▁Jim ▁Crow ▁laws ▁passed ▁between ▁ 1 8 9 0 ▁and ▁ 1 9 0 8 ▁by ▁white - domin ated ▁state ▁legisl atures ▁including ▁Alabama , ▁Georgia , ▁Louisiana , ▁North ▁Carolina , ▁Oklahoma , ▁and ▁Virginia . ▁They ▁restricted ▁vot er ▁registration , ▁effectively ▁prevent ing ▁African ▁Americans ▁from ▁voting . ▁Ra cial ▁restrictions ▁on ▁voting ▁in ▁place ▁before ▁ 1 8 7 0 ▁were ▁null ified ▁by ▁the ▁Fif teenth ▁Am end ment . ▁ ▁After ▁Democr ats ▁took ▁control ▁of ▁state ▁legisl atures ▁again ▁after ▁the ▁Comp rom ise ▁of ▁ 1 8 7 7 , ▁they ▁began ▁to ▁work ▁to ▁restrict ▁the ▁ability ▁of ▁black s ▁to ▁vote . ▁Par amil it ary ▁groups ▁such ▁as ▁the ▁White ▁League , ▁Red ▁Sh ir ts , ▁and ▁rif le