Answer:
The 14th Amendment to the U.S. Constitution, ratified in 1868, granted citizenship to all persons born or naturalized in the United States—including former slaves—and guaranteed all citizens “equal protection of the laws.” One of three amendments passed during the Reconstruction era to abolish slavery and establish civil and legal rights for black Americans, it would become the basis for many landmark Supreme Court decisions over the years.
Abraham Lincoln’s assassination in April 1865 left his successor, President Andrew Johnson, to preside over the complex process of incorporating former Confederate states back into the Union after the Civil War and establishing former slaves as free and equal citizens.
Johnson, a Democrat (and former slaveholder) from Tennessee, supported emancipation, but he differed greatly from the Republican-controlled Congress in his view of how Reconstruction should proceed. Johnson showed relative leniency toward the former Confederate states as they were reintroduced into the Union.
But many northerners were outraged when the newly elected southern state legislatures—largely dominated by former Confederate leaders—enacted black codes, which were repressive laws that strictly regulated the behavior of black citizens and effectively kept them dependent on white planters
