The 14th was designed to ensure that all former slaves were granted automatic United States citizenship, and that they would have all the rights and privileges as any other citizen. The amendment passed Congress on June 13, 1866, and was ratified on July 9, 1868
15th Amendment
The last of the Reconstruction Amendments, the 15th Amendment was designed to close the last loophole in the establishment of civil rights for newly-freed black slaves. It ensured that a person's race, color, or prior history as a slave could not be used to bar that person from voting. Though a noble idea, it had little practical effect for quite some time, as the Southern states found myriad ways to intimidate blacks to keep them from voting. The Congress passed the amendment on February 26, 1869, and it was ratified on February 3, 1870 (342 days).
Though ratification of the 15th Amendment was not a requirement for readmittance to the Congress of the Confederate states, one of the provisions of the Reconstruction Acts required that the states include a provision in their new constitutions that included a near-copy of the text of the 15th. All of the CSA states except Tennessee, which was immune from the Reconstruction Acts, eventually ratified the 15th Amendment.