The wheel

Most technologies consist primarily of ideas rather than artifacts, and therefore can be carried from one place to another inside people's heads. For reasons I'll note further down, it would have been impractical for a primitive wheeled contrivance to actually make the journey from Iraq to the Ukraine to Austria or vice versa. But a trader or adventurer who saw wheels in one of those places could easily take the idea home, where his own people could build their own. It's quite possible that we'll never know who invented the first wheel, nor if it was only invented once. As you noted, the Olmecs appear to have gotten the idea, so it's reasonable to speculate that like many technologies, the wheel was invented independently more than once.

Not to mention, a mountainous region is not a place that would inspire people to invent such a transportation technology. The grade makes it difficult for a draft animal to pull a cart or wagon, and the rough terrain reduces the speed of wheeled vehicles until springs and moveable axles are invented.

Stone wheels are relatively easy to build, but they're too heavy to be practical except on toys. You'd think that a cross-section of a tree trunk, with a little whittling, would make a perfect wheel. But its strength is in the wrong direction. Wheels have to be cut from boards (a vertical cross section of the tree rather than horizontal) which means their invention had to wait until fairly modern woodworking tools had been devised. Eventually the spoked wheel was invented, which has its strength in all the right directions, and in addition is very lightweight.

Still the speed, and therefore the usefulness, of animal-drawn wagons is limited by terrain. Without rubber tires (a very recent invention), wheels perform very poorly and disintegrate rapidly on bumpy dirt paths. When Bronze Age cities began to spring up, their administrators began paving roads to make transportation more efficient. Many of the ancient empires had road networks that were impressive even by modern standards. The American "Wild West" had many long roads that were unpaved, but they were reasonably well-graded, and the stagecoaches and other wagons which traveled over them had extremely large-radius wheels, in addition to leaf springs, to mitigate the bouncing.

There were bison, moose and mountain goats north of the Rio Grande, all of whom might conceivably have been domesticated (the bison has, but only quite recently), but civilization had not spread that far north by the time of the Christian occupation. Agriculture had arisen in what is now the USA and a number of animals had been domesticated, but aside from the dog (which was brought over from Asia by the original migrants) the largest domesticated animal was the turkey. Oddly, the "caribou" of our arctic zone is the same animal as the Eurasian "reindeer," but our arctic tribes did not domesticate it.

There were once bison in what is now northern Mexico, and there is a program to reintroduce them for their role in repairing the topsoil, but apparently they were killed off by the time Olmec civilization arose in the second millennium BCE. The Olmecs have the distinction of being the only people on earth who built a civilization without the help of draft animals. So, although they built their cities long before the Inca, they never had any reason to invent the wheel.

 

As has been noted:

• Neolithic cultures (the first non-nomadic humans, having invented the twin technologies of farming and animal husbandry, which both permit and require people to stay in one location) by definition had only stone tools ("Neolithic" = late Stone Age). The potter's wheel was rather quickly invented by sedentary cultures, and it's generally surmised that a runaway potter's wheel rolling down a slope was the inspiration for vehicular wheels. But larger stone wheels are too heavy to be practical for transportation.
• Wooden wheels are not easy to build, since the obvious way to make one, out of the cross-section of a tree trunk, doesn't have structural strength in the right direction. They have to be made out of boards, and stone woodworking tools are not very good for cutting boards. Wooden wheels were not invented until the superior tools of the Bronze Age were available.
• Even once you've got the dadgum wheels, who's going to pull the carts? The travois had already been invented in the Paleolithic Era. It could hold just about as much weight as a human (or dog) could pull (especially uphill, since cut-and-fill roadmaking was several thousand years in the future), and with only one point touching the ground it could navigate the rough dirt paths of the Stone Age. Putting a wheel on it would not have increased its speed or carrying capacity very much. Wheeled vehicles need something more than human- (or dog-) power to be worth the trouble of building. The large domesticated herbivores of the late Neolithic Era provided that power.
• Yet even with tame, trained goats, oxen or donkeys to pull carts and wagons, their usefulness is very limited until you've got reasonably smooth, reasonably level roads. Road-building of any magnitude is another technology that had to wait for the superior tools of the Bronze Age.
• This is why the wheel as we know it was invented in the Bronze Age. It was a brilliant idea that had to wait for its time.