In 1962, the net worth of the wealthiest 1% of Americans had 125 times the net worth of the median household.
That number is now 288, according to a study by the Economic Policy Institute. That study is discussed in this CNNMoney article. EPI's full report provides many more details. Note the chart below, which shows the considerable drop in median household wealth between 1983 and the present.
Wealth inequality in the United States, also known as the “wealth gap”, refers to the unequal distribution of financial assets among residents of the United States. Wealth includes the values of homes, automobiles, businesses, savings, and investments.[2] Those who acquire a great deal of financial wealth do so primarily through the appreciation of fiscal portfolios. For this reason, financial wealth involves only stocks and mutual funds, and other investments.