Early America: Africans from Angola and West Africa were brought to Boston in 1638. It was a small group of black men and women. A black community was born. It gained prominence through the 17th, 18th and 19th century. From 1950 to about 1970, redlining and racism caused Blacks to take root and displace the Irish and Jewish people living in the Boston communities of Mattapan, Dorchester and Roxbury. This disruption created a four zip code "Black Boston" part of town.
ASTROPHYSICS FOR PEOPLE IN A HURRY by Neil deGrasse Tyson, the popular host of a TV science show.