Reconstruction to Regression, post-1872

During Reconstruction, extensive progress was made in granting freed slaves more rights, towards their eventual equality with white people. The 13th Amendment ended the official institution of slavery, the 14th Amendment granted rights and equal protection under the law for all born in the US, and the 15th Amendment granted voting rights for all citizens within the United States, regardless of race. Steps to protecting African Americans from hate groups, such as the KKK, were taken through legislation like the Enforcement Act of 1871. However, after this brief period of growth, almost all of the rights of African Americans were stripped away again, essentially re-enslaving them.

Freedmen's Bureau Dismantled (1872)

The beginning of the end to freedmen's rights is most clearly seen through the dismantling of the Freedmen's Bureau. While some claim that objectively the Freedmen's Bureau was too under-funded to cause any significant growth or equality for freed slaves, the symbolic importance of the government no longer allowing an institution to exist that helps African Americans cannot be overlooked. Congress ended the bureau in the summer of 1872 due to pressure from the South.

President Hayes ends Military Reconstruction (1877)

In order to secure the vote for presidency, Hayes cut a deal with members from the Southern electoral college. Through this unwritten deal (known as the Compromise of 1877), Hayes agreed to withdraw northern troops from the South, effectively ending military reconstruction. With no one left to enforce Reconstruction or protect the rights of the African Americans, white supremacy and racism grew. 

Plessy v. Ferguson (1896)

This Supreme Court case introduced the idea of "separate yet equal", which later would form the political justification for segregation and Jim Crow laws. Through this ruling, the divide between races grew legally and proved the union of states would not extend to the union of races within America at this time. 

Sources

http://www.american-historama.org/1881-1913-maturation-era/plessy-vs-ferguson-case.htm
http://www.american-historama.org/1866-1881-reconstruction-era/segregation-history.htm
http://www.americaslibrary.gov/jb/recon/jb_recon_revised_1.html
http://www.history.com/topics/black-history/black-codes
http://www.history.com/topics/black-history/freedmens-bureau
https://www.khanacademy.org/humanities/ap-us-history/period-5/apush-reconstruction/a/black-codes
https://sites.google.com/a/email.cpcc.edu/black-codes-and-jim-crow/black-code-and-jim-crow-law-examples