There are five quintiles the government uses to show economic groups in the U.S. The top quintile (incomes about $94,000+) pays almost 84% of the income taxes. The quintile figure doesn't provide number of earners in a household, and most in that quintile have two earners, which lower the quintiles may not.
There are four groups tracked--Asian households have the highest income, then white, then Hispanic, then black. There are four pillars holding up the higher and upper middle earning groups--1) marriage, 2) higher education, 3) social capital by which they contribute to their community--local clubs, politics, sports, and 4) organized religion.
There are a lot of sources to check for this information: The CBO, https://www.cbo.gov/publication/49440 and Charles Murray "Coming Apart" (2012) and The Heritage Foundation to name a few. http://blackdemographics.com/households/marriage-in-black-america/ The Wikipedia article has a good bibliography, but is about 6-7 years old.