That used to be true, but the nation's very poor live mostly in the suburbs and rural parts of the country now. It shifted about 20 years ago. You can't go anywhere without encountering desperately poor people these days.
This is true. I live in a 30,000 person town in rural America that is a popular tourist destination for upper middle class types. Despite the cold winters, there is a surprising amount of homelessness - the city finally set up a camp area because they were concerned with the visibility to the tourists. Apart from a handful of white collar jobs (a small college, a hospital, a couple law offices), everything else is just above minimum wage, meaning even if you aren't homeless, there is limited mobility. Thankfully real estate is still very affordable, but as coastal cities push more people out of the market, even that is changing, as people move inland to find something cheaper.
