This piece by Russell Arben Fox is a little rambling and perhaps over-long, as is quite a lot of what he writes, but, again, as is quite a lot of what he writes, pleasingly knowledgable and suggestive. He argues that because the idea of legitimacy of a coercive authority presupposes some group for whom that authority is legitimate, political theorists should be more concerned about the creation of that group, and attacks social contract style theories because they suppose some universal human characteristic to draw the boundaries of that group, rather than being concerned with the historical creation of the group, its power structures and so on (he then goes on to talk about some bits of American history I don't know anything about really).
I'm suspicious of this: it confuses the proper tasks of history and of political theory, I think. Political theory is largely about laying out the conditions for the legitimacy of political arrangements, about the normative assessment of the structures of coercive authority imposed on individuals and groups. History is largely about describing how we came to be in the position that we are in. How we came to be in the position that we are in, the story of our predecessors, is not usually directly relevant to that position's legitimacy: the legitimacy of the current devolved government of Scotland, for example, does not depend on whether the Act of Union was binding on the Scottish people, but on whether the current devolved institutions fufill the requirements of legitimacy to its current citizens. There might be duties in the requirements of legitimacy that are historical - if African-Americans descended from slaves are owed reparations for their ancestors treatment, then the US government has a historically created duty to ensure payment of those reparations - but these strike me both as exceptional and as misleading. They fall under a general present-oriented account of duties - it's because there are harms now which these people are suffering from that we have, if we do, a duty to provide compensation - and a concern with history in the way I think Russell is advocating misses this.