The Black Codes were laws that restricted the freedom of African Americans during reconstruction. Even after the 13 and 14 amendments were passed, there were local laws that kept descriminating against blacks. Their righs kept being limited because of these laws. Many laws discriminated against blacks in the North and South. Blacks couldnt speak freely or testify agains white people. The end of the civil war was the end of slavery during that time, but it was not the end of racism.
The man holding the tree represents a black manholding on to the 13 amendment, and the guy in the water represents a racist white man who would rather fall in the waterfall then get help from the black man. The white man still doesnt follow the law because he is racist.
http://www.history.com/topics/black-history/black-codes
90 years after the civil war was over, brown vs board of education made segregation of schools unconstitutional. Since schools are run by local government, it took another 20 years to fully integrate public schools in the south.
http://www.publicschoolreview.com/blog/the-long-history-of-fairfax-county-public-schools