I believe it was split into 4 major parts.
Railroads were far more effective at transporting goods across the country without the risk or delay that comes with sailing. Canals while effective weren't as speedy or reliable as a train since boats are rather fickle things. The turnpikes were being used by wagons and carriages that I doubt could compete with Trains!
If they had invaded the battles would have gotten more allies killed then it would have done so instead of risking life’s the dropped the atomic bomb to prevent the loss of allied soldiers
<span>“I've always had great faith in and respect for our space program, and what happened today does nothing to diminish it.” I hope this helps you :) </span>