Final answer:
The 13th Amendment, ratified in 1865, abolished slavery throughout the entire United States, making slavery and involuntary servitude illegal, except as punishment for a crime.
Step-by-step explanation:
The legislation that abolished slavery was the b. 13th Amendment. The Thirteenth Amendment was passed by Congress on January 31, 1865, and ratified by the necessary number of states by the end of that year, officially ending slavery in the United States. It states that neither slavery nor involuntary servitude should exist, except as a punishment for crime where the party has been duly convicted. This amendment was a crucial step in ensuring the freedom of approximately four million people. Although the Emancipation Proclamation had previously declared the freedom of slaves in Confederate states, it did not abolish the institution of slavery as a whole. The 13th Amendment provided a more permanent and comprehensive solution by making slavery illegal throughout the entire country.
The 14th Amendment granted citizenship to all persons born or naturalized in the United States, which included former slaves, and provided equal protection under the laws. Meanwhile, the 15th Amendment sought to protect the voting rights of African American men. Both of these amendments, alongside the 13th Amendment, are collectively known as the Civil War Amendments, which greatly expanded civil liberties and rights for formerly enslaved people.