Tricky language problem, here, with "bred hostility". You could call it an irregular verb : I am fighting for civil rights, you are breeding hostility, they are fomenting a race war.

In essence, Reconstruction was the attempt by the northern winner of the Civil War to impose great changes in the slave society of the south. The reasons it did not happen are many, like intransigent southern whites utilizing the existing political system to regain power and terrorize and exclude freedmen from it, northerners unwilling to pay for a military occupation for the benefit of a racial minority they considered inferior and unimportant.

It's a sad story well told in Eric Foner's Reconstruction , and he aptly calls it an unfinished revolution. Troops were withdrawn, Whites regained power, Black voters and politicians were suppressed, and comforting myths about the Lost Cause and White paternalism were promulgated. It's possible to debate whether a limited federal government, as set out under the US Constitution, could long have allowed a northern majority to impose its will over the south, whether it was going to be an impossible task. But a good metaphor would be: if you say you're going to ferry a man across the river, push him out in a boat and then abandon him: can you claim you've done him favor by casting him adrift halfway? If, after great suffering and effort, he makes his way eventually to the other side, can you claim you helped him? C. Vann Woodward, in his classic The Strange Career of Jim Crow, would point at efforts in the south , notably the New South movement, to create a practical arrangement with free Blacks, to move on. Some schools for freed slaves were created, notably by the Quakers. But how much of this can be linked to the Freedman's Bureau, and Reconstruction?

Other people should chime in, here, but maybe the only thing Reconstruction did was , with the 13th Amendment, create the legal status of freed Blacks, create the legal grounds for them to be citizens. Citizens, who could eventually get to the other side of the river.