Ghettos in Poland
Germany occupied western Poland in fall 1939. Much of this territory was annexed to the German Reich. Eastern Poland was not occupied by German forces until June 1941. In south-central Poland the Germans set up the Generalgouvernement (General Government), where most of the early ghettos were established. Ghettos were enclosed districts of a city in which the Germans forced the Jewish population to live under miserable conditions. Ghettos isolated Jews by separating Jewish communities both from the population as a whole and from neighboring Jewish communities. The Warsaw ghetto, established on October 12, 1940, was the largest ghetto, in both area and population. There, more than 350,000 Jews--about 30 percent of the city's population--were eventually confined in about 2.4 percent of the city's total area.
Source: U.S. Holocaust Memorial Museum