yea, but they could never have built america like that in the 1800's, it is not only for personal transportation, or for transportation in general that the wheel is used, but also for thousands and thousands of other important things: e.g. the ruther from a ship or more mechanics within almost ever mechanical machine, like the engine of a boat, a train and so on..... u can find variations on that one thing called a wheel.
but one of the most used variations or uses for a wheel, is when it used to lift something very heavy, I don't know the english word for it, but you just throw a rope about a wheel hold in place in the middle, but stil able to turn around it's middle, it makes the lifting go far easier...
I guess someone will know what I mean.
and again I give the maya culture as example a very great culture which stopped evolving at one point because they missed a very huge invention (the wheel)