Not really. Beasts of burden are nice but dogs can (somewhat) fill that role and some potential domesticates already exist in Eastern North America like ducks (mallards), the Canada goose, and maybe squirrels which give protein to the people (Cahokia IIRC suffered a lack of protein at its height) and also their dogs. If the population is large enough, then many people will work as porters.
Obviously you have the rivers to move goods--in Mesoamerica and the Andes this is FAR less important. While the Mississippi is a lot more wild than the Nile, shipping down the river is very possible. In some tributaries it will be much easier. So many tributaries are navigable with kayaks and flatboats.
If the Mississippi-Missouri developed at the same time as Mesoamerica, or maybe a few centuries after and we had alt-Cahokia as a contemporary to the Olmecs, then odds are they would've surpassed Mesoamerica. The flat terrain and river transportation promotes much larger empires. It's a place where even without horses, you could have an empire from the Gulf to the Great Lakes, bounded by the Appalachians on one side and fading onto the Plains on the other. This would be your alt-Aztecs I guess, although such an empire is by no means inevitable.
I think they'd end up developing metallurgy (beyond the copper working present OTL) and would smelt copper, gold, lead, and whatever else was available. I don't know if they'd smelt iron although it's readily available.
I think we'd have a site further south emerge first as maize agriculture becomes firmly established, contemporary to the Olmecs, maybe in the Delta region. This culture is our Olmec-equivalent. They decline and the center moves further north around the Roman Warm Period to Cahokia and they are our Teotihuacan, exerting an incredible cultural force in addition to building their own empire in the region. After they collapse around the 6th century, there's a multitude of states and centers, some very influential (i.e. Toltecs), and one of which will eventually establish a major empire. There's obviously many great sites for cities in this region, so could be around Little Rock, St. Louis (i.e. renewed Cahokia), Paducah, Nashville, Florence, Huntsville, Louisville, etc.