One cause of the unparalleled material abundance of the US in the 1950's was is a population increase of about 30 millions. Thank you for posting your question here at brainly. I hope the answer will help you. Feel free to ask more questions here.
By declaring independence and not sparing any money.
It depends on the time period. I would say its true back around the 1800's, but around closer to our time, it is false. I hope this helps! ^^
