I have been trying to place my head around this idea and am looking for help to understand in modern terms. We all know that when Europeans came to the New World it was pretty advanced civilizations basically stepping back into the stone age. In terms of today's technology and knowledge etc.; how far back in history would a modern civilization have to go to have the same superiority of advancement? Would it be Civil War time period? Earlier, later?

I'm not sure you have to go back that far. It seems like technology has advanced pretty quickly in the last 50-60 years.

That is why I am having difficulty placing a timeframe in my mind. I suppose one could argue WWII, The communication and logistic advances alone would make those armies look like they were operating in slow motion.

Not really following your question but disagree with the premise of European settlers stepping back into the stone age, they took their tools with them and did all they could to rapidly transform the wilderness into the comforts of home. Different dangers were faced in the New World but life was short and hard in both places,

That is what I am saying. If a modern civilization could go to a point in time still having access to tools they used in modern times and start building up to today's standards, how far back in history would that civilization have to go to match the difference in the civilizations. The Europeans at that time were very advanced, but the civilizations they encountered were still operating in close to stone age standards. Where is the point in history to get the same disparity compared to today's civilization?

I think you have to look at it in terms of major advancements in civilization. Stone age, bronze age, iron age, gun powder, steel, steam power, internal combustion engines, electricity, electronics, space travel, internet, cell phones. It will depend on how many advancements there are between the two groups or eras you are looking at. Advancements are much more frequent now but most seem to be smaller steps. Earlier advancements were in agriculture, weapons and transportation. Recent developments are more in communication and data which you may or may not notice. I think it would be very hard to quantify since the advancements are in different aspects of life.