I wouldn't say George Washington and Jefferson were necessarily liberals. I know Jefferson owned slaves and pretty sure Washington did too. They were involved (although a few degrees away from the source) in the colonization of another's land (ie the Native Americans). It would be like the French colonist in Indochina proclaiming their independence from France. It's still not their land.

I think a better example would be every act of social change over the last 5 decades has begun from a liberal or working class ground swell (we're certainly talking radical anarcho-syndos here. There are regular joes).