None of those families were middle class.

But hired help has certainly gotten less common. The cost of labor went up, faster then the wages of middle class families. With stronger minimum wage laws, welfare, and subsidized education, there was less unskilled labor willing to work for low enough wages to make them cost effective for most families. Also, the cost of labor saving technology went down, further decreasing the need for hired help.

Lind, Michael. Land of Promise: An Economic History of the United States. New York: Broadside, 2012. Print.

It's also worth noting, that if we dropped minimum wage and returned to mostly open borders, the middle class could afford domestic help again, as starving Haitians would work for dirt cheap and still increase their current standard of living.

This answer has attracted an incredible number of bad answers, partly because of the way it's phrased, and so I have removed it. If you wouldn't mind resubmitting your question without the parts about the modern day, it should be OK.