Just over 50 years ago, on June 26, 1976, I graduated from high school. Along with 700 other “bicentennial seniors,” I received my diploma on a stage decked out in red, white, and blue bunting celebrating the country’s 200th birthday. Though almost all white, my classmates and I were not homogeneous. Our town, Trumbull, Conn., was heavily blue-collar. But it was changing quickly, as large corporations like General Electric moved their headquarters and executives into the area.