From the (1939) WPA Guide to New York City:
Brownsville extends from Ralph Avenue to Junius Street, between Liberty and Hegeman Avenues. With more than two hundred thousand people dwelling in its 2.19 square miles, it is the most densely populated district in Brooklyn. The population is predominantly Jewish. A group of Negroes lives on Rockaway Avenue, Thatford Avenue, Osborn Street between Livonia and Sutter Avenues. The only Moorish colony in New York is on Livonia Avenue between Rockaway and Stone Avenues. Italians live in the northern section of Brownsville; and on Thatford Avenue near Belmont is a small Arabian and Syrian quarter.
The main thoroughfare, Pitkin Avenue, named for John R. Pitkin, founder of the village of East New York, has large shops, a movie palace, and restaurants; great crowds of shoppers and strollers, day and evening, offer a colorful contrast to the numerous side streets with their dismal houses. The open-air pushcart market on Belmont Avenue, from Christopher Street to Rockaway Avenue, is the cynosure for local housewives, wives, who come to make thrifty purchases. Here Yiddish is the shopkeepers' tongue, and all the varieties of kosher foods, as well as delicacies particularly favored by Jews, are the leading articles of sale. In winter the hucksters bundle up in sweaters and stand around wood fires.
The area now called Brownsville, lying between the villages of East New York and Bushwick, was subdivided by Charles S. Brown in 1865. In 1883 there were 250 frame houses in the village. A group of East Side realtors in 1887 purchased land and erected many dwellings. They encouraged immigrants, chiefly Jews of East European origin, to move here from Manhattan's congested East Side. The extension of the Fulton Street el in 1889 and the IRT subway in 1920-22 made the district completely accessible from Manhattan, where many of the inhabitants work.
Old World customs dominate Brownsville life. There are more than seventy orthodox synagogues; the first, Beth Hamidrash Hagodal, at 337 Sackman Street, was organized in 1889. Numerous cheders, where young Jews receive instruction in orthodox traditions and customs, dot the neighborhood. On Friday night on Jewish holidays the streets of Brownsville are hushed. In all orthodox homes, after nightfall on the Sabbath eve, candles gleam, offering the only light in the room.
Numerous landsmanschaften, societies organized by immigrants from the same town or village in the Old World, supply most of the social life for the inhabitants. The landsmanschaften are also mutual benefit societies in which regular payments guarantee a doctor's service in case of illness, and a burial plot in case of death.
The building trades claim many Brownsville residents, and on Sunday morning, on the corner of Stone and Pitkin Avenues, carpenters, painters, electricians, and masons assemble to talk shop and find employment. Boss painters and contractors walk from group to group, picking their men. Behind the assembly rises a forlorn building, once a branch of the Bank of the United States, whose sensational bankruptcy in 1930 brought enormous losses to Brownsville residents.
Brownsville has always been hospitable to new social movements. From 1915 to 1921 this district elected Socialists to the New York State Assembly. In 1936 an American Labor Party candidate was elected to the Assembly, only to lose his seat in 1938. In 1916 Margaret Sanger established on Amboy Street the first birth control clinic in America.