Answer:
A "Shantytown" is a neighborhood consisting of collection more-or-less permanent semi-urban residences constructed from improvised building materials (plywood, plastic, sheet metal, cinder block, etc.) The most obvious examples are found in the South African townships, like Soweto, in Haiti, and in the hills outside of Caracas, Venezuela. Shantytowns may be found in every under-developed country with a landless, displaced or refugee population.
Shantytowns are rarer in the industrialized west, although during the Great Depression they were common in American cities. Also called "Hoovervilles," they were named for Herbert Hoover, who was US President 1928-1932, and were populated by newly homeless subsistence farmers, immigrants, agricultural, and industrial workers and their families. In New York City, there was an extensive Hooverville/shantytown on the west shore of Manhattan, along the NY Central RR tracks on the upper west side, where Riverside Park now stands.