Is it possible to comapre the economic situations of the people as to at which point the status quo became unbearable in tems of income and wealth inequalities, peoples' pain, national debt etc.....this will tell us where we are now!
We can, I believe, draw very useful parallels and thus lessons from those moments when huge changes were produced. But we need also to be attentive to the uniqueness of each moment. A great political leader once said: "For decades nothing seems to happen, and then, suddenly, in a few weeks, decades happen." That is one lesson to keep in mind. Grievances accumulate slowly into a state of intolerability. Likewise those aggrieved have to be able to see, top identify some social force that at least has a chance to really change the situation. If the see such a force but it fails them, they will likely be all the more reticent about trying again. Thats why it all takes those long decades when "nothing seems to happen." But if there are alert folks who participate all along and evaluate the situation continuously, then you may have that magic combination of (1) an intolerable situation, (2) loss of confidence in existing leaders and institutions, and (3) reasonable hope in alternative leaders and alternative institutions - that enables those great historic turning points.