The relative equality of Americans before 1776 has been overwhelmed by a thousand forms of physical, mental, and economic differentiation, so that the gap between the wealthiest and the poorest is now greater than at any time since Imperial plutocratic Rome. In progressive societies the concentration may reach a point where the strength of number in the many poor rivals the strength of ability in the few rich; then the unstable equilibrium generates a critical situation, which history has diversely met by legislation redistributing wealth or by revolution distributing poverty.