>>22242
All civilisations need a staple crop to provide a food surplus, which means that people can move from nomadic lifestyles to settled civilised lifestyles.
In Mesoamerica, Maize filled this role. In the north, Maize wasn't present until it arrived from Mesoamerica and the neolithic thus began in what is now the Southwest, Southeast and Midwest of the US. By this time, Mesoamerica had advanced beyond the neolithic.
Of course, other crops than Maize were domesticated in this region (Squash, Beans, Tomatoes) but to my knowledge Maize was the staple, as Wheat/Barley was/is for most of Western Civilisation.
Other factors come into play, such as difficulty of the environment. If you look at most places where agriculture began (e.g. Mesopotamia, Yellow River Valley, Papuan Highlands), they're all fairly marginal areas. In the most agriculturally productive areas today (Eastern US, Northern Europe), people remained hunter-gatherers for much longer. The theory is that as the last Ice Age waned, populations of foragers swelled so much in less productive areas that people there were among the first to be forced into adopting agriculture. They could no longer sustain hunting and gathering in such infertile lands.
Thus, we see the people of Mesoamerica adopting agriculture before other native peoples, as Mesoamerica's productivity is plagued by long periods of drought and poor soil (I think - I may be wrong).
Sorry that I didn't address the Andean peoples in this post, I don't know what crops they grew or what the environment is like in the Andean highlands.