What arguments were made in favor and against the 15th Amendment in 1870?

The 15th Amendment to the Constitution, ratified in 1870, prevented the denial of the vote based on race, color, or previous circumstance of servitude. In essence, it gave African American men the vote and was a cornerstone of the Reconstruction era. The Republican-dominated Congress ratified the Amendment, although it was opposed by then President Andrew Johnson, who attempted to veto it.
Still, it passed and had an almost immediate impact on the political culture of the US. For the first time, several African Americans were elected to Congress only a few years after being freed from slavery.
Much of this transformation was too drastic for the entrenched culture of racism in the Southern United States. Southerners fought back against the imposition of the 15th Amendment with laws that prevented African Americans from voting at the state and local level. These Jim Crow and segregation laws more generally rolled back the advances pushed forward with the 15th Amendment.
These discrepancies were only fully resolved when the Voting Rights Act was passed in the US in 1965, ending all the limitations on the African American vote, once and for all.