Just when did the income inequality begin to run rampant?

I keep hammering at the problem of income inequality because it is bringing America to its knees. When so few people own so much of a nation's wealth, there's just not enough left over for the people in the middle to survive. And the Republicans, the wealthy ones anyway, are hammering at ever more ways to get the rest of the money. They won't be happy until there is a huge underclass of very, very poor people who will work for them for subsistence wages, live in their company towns and service their fat-cat lives. THAT's what conservatives, the wealthy ones anyway, wish to return to.