Why didn't a significant civilization develop along the banks of the Mississippi River?

Ok, let me preface this by saying I do have a degree in Native American Studies so I have some knowledge on this, but I got the degree basically as just something I'm interested in, I am a music teacher by trade.

That said, here is my OPINION.

If you look at the amount of resources that existed in North America (and still do) there wasn't a need to become sedentary and begin agriculture. If you do some research you will find that of the worlds food sources something like 85% (I'm pretty close on that number but it might be off somewhat) are Native American in origin. Including things like potatoes and tomatoes.

I think the key for civilizations to progress tecnologically is for there to be a need. In the case of North America there were such abundant resources that there was no necessity to make the jump from broad-based hunter gatherers to farmers.

I cannot speak directly for tribes along the Mississippi as my expertise lies more with the Great Lakes tribes but if you look into them you will find things that I would at least define as divisions of labor, social hierarchy, political organization (pretty complex in fact). None of the North American tribes developed a formalized written language (nothing beyond pictograms) and I don't think you would ever find a long term economic surplus. There were "cities" in what is now the South Western U.S. that were larger than London, Paris, or Rome at the same time in history but they broke up. It is believed that they ran into problems with diseases and the cities scattered.

So I think if you look you will find some of the things you consider in you definition of a civilization but certainly not all. My belief is that this is due to the abundant resources that could be found naturally so the tribes that existed here never progressed into an agricultural society that stayed in one place that would give them enough time to develop these other things.

I still think that flooding and storms in the Gulf of Mexico would have played a major role in civilizations not developing. Control of the Mississippi is still a problem and transportation was too slow until the steam boat came along.

"Major" civilizations rise in opposition to other powerhouse countries. For example, Egypt had to contend with the Phoenicians, Greeks and Romans. China had the Mongols and Indochinese.

By contrast, North America was inhabited by roaming tribes that didn't come into major conflict with each other. Tribes followed the food, but rarely had HUGE migrations. A herd of bison may only travel a couple of hundred miles. Fish were abundant most of the year. Wild fowl may migrate, but when the geese go south, the deer are still there. Abundance of natural resources kept them happy. Oceans kept them out of conflict with alien cultures. Lack of conflict means little need to fortify and strengthen into a "nation".