This is an excellent report from the Heritage Foundation on the definition of poverty in America and how that definition has changed over the decades.
From the abstract:
For decades, the U.S. Census Bureau has reported that over 30 million Americans were living in "poverty," but the bureau's definition of poverty differs widely from that held by most Americans. In fact, other government surveys show that most of the persons whom the government defines as "in poverty" are not poor in any ordinary sense of the term. The overwhelming majority of the poor have air conditioning, cable TV, and a host of other modern amenities. They are well housed, have an adequate and reasonably steady supply of food, and have met their other basic needs, including medical care. Some poor Americans do experience significant hardships, including temporary food shortages or inadequate housing, but these individuals are a minority within the overall poverty population. Poverty remains an issue of serious social concern, but accurate information about that problem is essential in crafting wise public policy. Exaggeration and misinformation about poverty obscure the nature, extent, and causes of real material deprivation, thereby hampering the development of well-targeted, effective programs to reduce the problem.
One note: Heritage does not make the same mistake as liberals and say that we can solve the problem of poverty, just reduce it. This has always been one of the biggest obstacles to addressing the issue of poverty - our own high flown expectations about what can be done about it.
It's a long read but well worth it.