Dirt Poor – This phrase dates back to the 1930’s Depression era where there was extreme poverty and many people lived in dirty conditions.
The source that claims it comes from England at an earlier date has largely been discounted. An article about “Life in the 1500s” circulated on the internet in April 1999 and according to Snopes is nothing more than an extended joke, someone’s idea of an amusing leg-pull. All of the historical and linguistic facts it purports to offer are simply made up and contrary to documented facts.