Oh my god, yes. I'm assuming that you are talking about US history. Let's start at the beginning, i.e. with the American Revolution. Commissioned officers in the militias were very much based around the upper class. It actually became a huge sticking point for the lower classes, and many simply refused to fight until the officers made some concessions to them. At the time, being an officer was almost entirely in the purview of the elites, a fact which irritated everyone else since the revolution was supposed to be about equality.

This mindset continued well into the nineteenth century. Soldiers made the same complaints during the War of 1812. In South Carolina there was a petition to the state government that the militia corps "promoted aristocracy" among the officers.

As you might suspect, this problem persisted much longer in the South. Militia units were a part of the social, as well as military life. Slave patrols consisted of militia members, and there was a certain degree of prestige in being a militia officer. You got to call yourself Colonel, or whatever. Once again, the upper class dominated these positions since they had political influence and could promote themselves as officers.

The change really occurred after the Civil War, when the US moved towards a professional army, rather than relying on militias for the backbone of their force. There was still a class element for a long time, though. Only the upper class could regularly get their children into the military academies that spawned officers. It did move more towards egalitarianism, however, as the schools opened up more.

Sources: Woody Holton, Forced Founders, Bertram Wyatt Brown, Southern Honor.