History. Will give brainliest

I believe it’s the third option :)

Econstruction was a period of profound change in all aspects of American life. The fundamental question that agitated the country in the period after the Civil War was how our society would respond to the destruction of slavery. What system of labor would replace slave labor? What [*1586] system of race relations would replace the race relations of slavery? What would be the role of former slaves in American civic life? More broadly, who was entitled to American citizenship, and what rights were those citizens to enjoy? Would they be protected by the newly empowered national state? These questions became the focus of a tremendous political struggle in which African Americans themselves played a central role by demanding that the nation give substantive meaning to the freedom they had acquired.As a result of this crisis, Congress and the states enacted a series of laws and constitutional amendments that for the first time in American history established as a matter of federal law the principle of equal rights for all citizens regardless of race. n1 In addition, black men received the right to vote in the South in 1867 n2 and then throughout the nation via the Fifteenth Amendment in 1870. n3 More broadly, Republicans tried to embed the concept of equality among Americans (a principle not mentioned in the original Constitution) into our laws and social reality. n4