Because humans are never content with what they have there are only two ways to continue a greedy ,hoarding life style..   the first is war.  the kind where you run across town kill everyone, grab their stuff and your set for a few months.  needless to say #2( slavery) put an end to that.   OR WAS IT THE BEGINNING. Its hard to believe so many people cannot see the big picture of anything  anymore.  but that would be another story too long to explain and most peoples minds have been altered to realise everything you ever wanted to know is already in there.           Anyway,  how glorious to know were the great melting pot of the world.  no other country has ever been able to enslave such a large multitude of cultures at one time.     instead of being worked to the bone  we all have a little part  .  Sorry im running out of time, heres a little homework... see how many rich people,corporations and those in washington have ties(ancestors) to the largest  plantations of the past.  oh dont forget the mexicans ( i think we need a bigger pot)