The end result of the Civil war was the eradication of the insidious institution of slavery, and thereby the freeing of those previously enslaved, that were also thereupon granted per the highest law of this land, citizenship, equal protection of the laws, as well as the right to vote. All of this, sounds quite good on paper, but good laws that are not enforced are hardly good laws at all. Additionally, in 1865, most slaves were not only illiterate, but were rather rural in the substance of their labor, they also owned no property, so that the freeing of 3.5 million peoples, that own no land and had no property was not in and of itself, going to provide a fair opportunity for those previously enslaved to become self-supporting and truly viable as well as liberated members of society.
In an era in which the southern rebellion had been put down, and in which, the vast majority of former slaves were physically located within those rebellious States, all this should have been recognized as being the proper and the best time for the Federal government to take proactive measures to provide to these illiterate and agrarian based former slaves, with the land, seeds, and tools, so as to make these people, self-sufficient and to secure their freedom and prosperity.
While it is true that the Federal government did provide some material aid to those previously enslaved, in conjunction with and alongside of religious organizations, and volunteers, that helped to educate former slaves as well as to enforce and to protect Constitutional law within those States, it was not enough overall to provide meaningful change for the vast majority of those previously enslaved. That is to say, for the most part, those of the powerful planter class of the south that had rebelled against this Union of States, that produced untold misery and bloodshed upon the peoples of the same country, were able to upon the end of hostilities and the peace so made, go back to their lands, in most cases, with full rights to such, as opposed to their lands being rightly confiscated and being provided to those without land, including poor landless southern whites, as well as previously enslaved and landless blacks.
So that, while blacks were now citizens, with, in theory, equal protection of and access to judicial law, as well as the enfranchisement of the vote, it did not take long for the plantation ruling class of the south to assert themselves in such a manner, that things were about the same as they were during the institution of slavery, with the exception that rather than having and owning slaves, those that work the land for that plantation ruling class, were now designated as sharecroppers instead.
All of this really meant, that freedom, without the accouterments of what people actually need to be truly free, as represented by adequate education, the fair compensation of the fruits of one's labor, as well as the means for the ownership of land, meant that those that had been enslaved were in effect, free on paper, but still oppressed and subjugated, in actuality.