18 …1912: Black boxing champion Jack Johnson is arrested in Chicago, accused of violating the Mann Act because of his relationship with his white girlfriend, Lucille Cameron.... President Trump pardons him posthumously in 2018.) Also on this day: 1648: Boston shoemakers are authorized to form a guild to protect their interests; it's the first American labor organization on record.... 1898: The American flag is raised in Puerto Rico shortly before Spain formally relinquishes control of the isla