Millionaire Population in America Grows Number of households with more than $1M in assets up to 5.5M By Nick McMaster, Newser Staff Posted Sep 16, 2010 5:59 PM CDT 57 comments Comments The number of American millionaires is on the rise. (Shutterstock) (Newser) – The number of millionaires is on the rise again. The population of rich Americans has been growing over the course of the year, even as the economy has stuttered over the first half of 2009 and poverty has increased. In the 12 months ending in June, the number of American households with assets over $1 million grew 8%, to 5.55 million, the Wall Street Journal reports. That's after two years of declines. The increase suggests a further divide between the economy of the wealthy and that of the middle-to-lower classes. In fact, the richer millionaires are having an even better 2009: the population of those with $5 million in assets grew by 16%, and the number of those with $10 million grew by 17%. Of course, this is still way below the level of millionaire-creation from before the financial crisis, when the millionaire population grew by 35% a year at its peak.