He who controls the past controls the future

and , much like today , half the country didn't like that

Look up voting and citizenship laws in Northern and Western states before the 13th 14th 15th Amendments. Most free blacks could not vote and were not citizens. Attitude toward black folk, North and South, was similar.

You can't change someone's attitude overnight. If you think that winning the war should have changed everything and change everyone's attitudes towards others, you would be ignorant.

My point was people's attitude before the war. Very few people at the time considered that the war was fought to free the slaves. Lincoln made that clear.

“My paramount object in this struggle is to save the Union, and is not either to save or to destroy slavery. If I could save the Union without freeing any slave I would do it, and if I could save it by freeing all the slaves I would do it; and if I could save it by freeing some and leaving others alone I would also do that. What I do about slavery, and the colored race, I do because I believe it helps to save the Union; and what I forbear, I forbear because I do not believe it would help to save the Union. I shall do less whenever I shall believe what I am doing hurts the cause, and I shall do more whenever I shall believe doing more will help the cause."

The Collected Works of Abraham Lincoln edited by Roy P. Basler, Volume V, "Letter to Horace Greeley" (August 22, 1862), p. 388