The Doctor: Herbert Hoover. Thirty-first President of the USA; came to power a year ago. Up 'til then, New York was a boom town, The Roaring Twenties and then…
Martha: The Wall Street Crash, yeah. When was that, 1929?
The Doctor: Yeah, whole economy wiped out overnight. Thousands of people unemployed. All of a sudden, the huddled masses doubled in number with nowhere to go. So they ended up here in Central Park.
Martha: What, they actually live in the park? In the middle of the city?
(Martha and the Doctor walk through Hooverville)
The Doctor: Ordinary people lost their jobs. Couldn't pay the rent, they lost everything. There are places like this all over America. No one's helping them. You only come to Hooverville when there's nowhere else to go.