Misesian Consumer-Sovereignty sense of the word.
I agree with you "we" (blacks, indians, women, and poor whites) are freer now then we (to degree and percentage by category) were from 1860 going back.
I do not believe "liberty" in the Misesian sense can be achieved via voting and lobbying because the ballot box is NOT a free-market good or service -- it is a corporatist one and can therefore only bring about corporatist type results.
I'm sure certain people are freer under a Dictatorship then are under American Corporatism -- it's how things shake out for the rest of the society (under said Dictatorship) that begs the larger question.
In this instance are blacks-indians-women freer now then they were 1930 going on back -- the answer is 1000% yes yes yes.
And going back for most poor whites (from 1860 on back) is yes yes yes as well.
*&^ Constitution --- Constitutional Rationality