The "long hot summer" refers to the summer of 1967, which began a year in which 159 race riots erupted across the United States.[1]
In June in there were riots in Atlanta, Boston, and Cincinnati, as well as the Buffalo riot in (Buffalo, NewYork), and a riot in Tampa, Florida.
In July there were riots in Birmingham, Chicago, New York, Milwaukee, Minneapolis, New Britain, Conn., Rochester, N.Y., and a riot in Plainfield, New Jersey. The most serious riots of the summer took place in July, with the riot in Newark, New Jersey and the Twelfth Street Riot, in Detroit, Michigan.
As a result of the rioting in the Summer of 1967, and the preceding two years, President Johnson established the Kerner Commission to investigate the rioting.