Every Juneteenth, as soon as Pamela Baker got to Booker T. Washington Park, she’d race to the merry-go-round, squeeze through the swarm of shrieking kids, grab one of the shiny rails, and hold on tight. After a few minutes, she would jump off and dart up the steps of the nearby dance hall to survey the throngs below. She and her brother Carl would weave through the crowd, looking for cousins from Dallas and Houston they hadn’t seen since the previous year. Eventually, her whole family would co...