Ancient Rome is often cited as a republic/democracy, and one of the earliest examples of a civilisation enforcing some degree of human rights. However, it's no secret that slavery was present in Rome. So, I want to know the rights that various classes of people held during the Republican era (c. 500 - 27 B.C.), e.g. slaves, women, artisans, etc.
There's a pretty good discussion of this here: http://www.vroma.org/~bmcmanus/socialclass.html
Briefly, in the early republic, the populace was divided into the plebs (common people) and patricians (aristocracy) with most public offices reserved for the patricians. Over time, this evolved into more layers, with the senatorial class (highest) followed by the equestrians, commons, freedpeople, and slaves. By the time of the late republic, some of the most powerful offices (eg., tribunes of the plebs) were open to commoners (although they were often occupied by members of the equestrian class, who had the resources to campaign for election).