What were some of the biggest barriers to the success of the 15th amendment

This amendment is part of the amendments ratified in the Recosntruccion period, its main barrier, was produced when the government removed its army from the southern states, from that moment the so-called Jim Crow laws were born that made it impossible to segregate racial, and the grandfather clause also arose, which only allowed people whose grandparents smell it in the past to vote, for this reason most Afro-Americans could not exercise their civil rights.

answer; self-efficacy;

i truly dont know the answer wait i do its 1,3,4