Compared to other countries, a factor of 16 is paltry.
Compare the “Wealth Gap” in America to the wealth gap in India (between Brahmins and the lower castes), or in Brazil, or Venezuela, or - for that matter - China, where cooks and nannies can be hired for a few dollars a day.
The wealth gap actually started right around the start of the industrial revolution. That was the era, from 1850 to 1900, when many enterprising young men became wealthy thanks to the invention and implementation of the explosion of technology and innovation.
But it was also the era of American history with the greatest pct. of increase of wealth for the average American worker. The fact is before the industrial revolution there was a very small segment of society with money like large landowners and merchants and traders.
After the i.r., the prospects for many more enterprising people became greater.
So what you had from 1850-1950 is the growth of a middle-class with people living far better lives than their predecessors from one hundred years before. Or just 20-50 years before.
Today the very wealthy have a lot more wealth. But the average middle-class person also has far more wealth. But because for obvious reasons a professional usually will make more money than a person with say a skilled trade, the gap will always grow.
Again, that does not mean the average worker is living a horrible life. Most average Americans live good lives. It just means that while they have more wealth, some people make percentages more. The only way to correct this "problem" is thievery i.e. communism.