How long did it take for America's democracy to stabilize? And what were the problems?

I was just looking at news footage of an Iraqi expressing his displeasure with the United States for "not bringing democracy as promised". I can understand his frustration but I think his judgement is hasty. I'm uming this transformation takes a considerable amount of time...as in decades. So I'm wondering how long it took for our democracy to become stable, and also if some of the problems can be overcome with current information and communication technology...or maybe it's not that simple and we do have decades to endure before there is the stable peace in Iraq that we all look forward to.