The number of Americans living in poverty rose to a record 46.2 million last year, official data has shown.This is the highest figure since the US Census Bureau started collecting the data in 1959.
In percentage terms, the poverty rate rose to 15.1%, up from 14.3% in 2009.
The US definition of poverty is an annual income of $22,314 (£14,129) or less for a family of four and $11,139 for a single person.
The number of Americans living below the poverty line has now risen for four years in a row, while the poverty rate is the biggest since 1993.
Poverty among black and Hispanic people was much higher than for the overall US population last year, the figures also showed.
The Census Bureau data said 25.8% of black people were living in poverty and 25.3% of Hispanic people.
Its latest report also showed that the average annual US household income fell 2.3% in 2010 to $49,445.
Meanwhile, the number of Americans without health insurance remained about 50 million.
The data comes as the US unemployment rate remains above 9%.
President Barack Obama last week launched a new $450bn job creation plan.
He wants to fund huge construction projects, schools and services, while giving tax cuts to workers and small businesses to boost recruitment.
However, his plans require backing from Congress, where Republicans - who control the House of Representatives - have voiced their opposition.