1969: In the wake of the assassination of Reverend Martin Luther King the year before, dozens of cities across the country—including Chicago, New York, Baltimore, Boston, Newark, Kansas City, and Washington, D.C.— experience race riots. Some black communities are completely devastated by the riots.

Today: Racial tensions seldom boil over into riots. The last major spate of race riots occurred in 1992, after the verdict was handed down in the trial of the Los Angeles police officers who arrested Rodney King.

1969: Americans look nostalgically toward the wholesomeness of country life as an antidote for the violence and corruption of inner city life.

Today: "Urban sprawl" has pushed Americans beyond the crowded city into the semi-rural comforts of the suburbs.

1969: Only a few black actors are offered recurring roles on network television, most notably Bill Cosby in I Spy, Diahann Carroll in Julia, and Nichelle...