Our ancestors as slave owners

I just read and commented on a ladies blog about her 3rd great grandfather being a slave owner and fathering children by his slave and then keeping them as slaves. It is beyond my comprehension how a person could do this. I've seen the movie Roots several times and it is a fantastic look into our past as a nation. But what amazed me is how the people of the time could have these high morals and go to church every week and turn around and beat and maim their slaves plus father children by a race that they allegedly dispised and act as if everything is just hunky-dory. With respect to this ladies 3rd great grandfather and many on here who had ancestors who were slave holders,do you realize how cold and hard hearted these people must have been ? If your religious can you imagine going to church on Sunday and praying and doing whatever and then go home to your farm or plantation to slaves that you have beat or maimed and are living in squalor and supporting your sorry rear ? Not to mention the children they had by some poor slave girl or woman and then keep your own child in slavery ? As a human being how is this possible ? How can anything of this nature be done in America and be justified ? Is there any justification to it ? America is not the only country that is guilty of slavery,slavery goes back thousands of years in all parts of the world with all types of people and races. But one would think that in a country, where such as ours even though it was young, would have been above this type of moral and intetellectual decadence. The sad part even today is we,as a nation,put some of the very slave owners,the very people who added to the misery of slavery,on a pedestal and call them "fathers of our country" and heap accolades on them as great men. How is it possible to hold these persons in such high esteem and then ignore what they did to a race of people ?