They disliked the African Americans because they were brought over to America as slaves, and the White people still looked at them as slaves. Not real people. They didn't think the two colours should be mixing.
Blacks were brought to America as slaves. Even after the abolition of slavery, they were viewed as that class of citizen. And I don't think "hate" is the right word. Maybe looked down upon as a class. As with most things, times have changed - or changing.
Partly human nature to hate what is different and partly because of a once popular religious belief that black races were descedants of Cain and therefore marked by God as inferior and undesireable. Today its just tradition and because people with african descent were once slaves, tho sadly there are still some old school denoms that STILL buy that 'mark of Cain' stupidity.
Because people can be extremely ignorant. They fear what they don't understand. They want to feel power I ever what they fear. There is no good reason. You can't really justify ignorance. I have wanted all my life to see thus change in this country. I always repeat something I heard said many years ago by Maya Angelou. "We did the best we could with what we knew. When we learned better, we did better." I hoped that before I die, race would be a complete non issue in thus country. I'm 60 years old........... .............doesn't look like thus hope will be realized.
Are you speaking currently or in the past? Speaking of slavery, America didn't "hate" the negro, they exploited the African tribes/cultures/whathaveyou. Slavery at the time was not uncommon - Africans had African slaves, Europeans had European slaves, Native Americans had Native American slaves. The Europeans simply took cross-culture slavery in America to a much greater level than ever seen before.
With slavery comes degredation. Since slaves were viewed as property they were treated as such, and disciplined as such - much the same way you have good and bad pet owners. It was ingrained in peoples' and society's mindset, and some people - either because they use it to validate negative experiences, or just being "a bad egg" - still carry those negative feelings of inequality with them.
Every culture in history has had its slaves/untouchables. All you have to do is watch school-kids today (in any culture), to see that its just part of the human condition. There's never had to be a good reason to hate. WE just need to recognize our part in it as reasoning adults, and change it... Not just substitute a new underdog.
I believe that the American in those years were ignorant and full of hipocracy. Christianity then like it is now taught that man was created equal and God doesn't judge a man by their skin but what's in his heart. I don't know why they had a mentality like that but I'm glad our great president Abraham Lincoln signed into law the emancipation proclamation and let all slaves be free. That didn't stop Americans from being prejudice but it was a start for the African American to have a voice
Our country has some very ugly skeletons in it's closet. They were brought over as free labor and treated worse than dogs. Slave owners set the tone first. Their children learned from them, and so on and so on. Maybe some people hated what they feared, based on lies.