1930s: Mary McLeod Bethune becomes the first African-American woman to receive a major appointment from the U.S. government when she is appointed the director of Negro Affairs of the National Youth Administration.

1950s: Jackie Robinson is named director of communications for NBC (National Broadcasting Company), becoming the first black executive of a major radio-TV network.

1990s: Oprah Winfrey becomes the first black woman to own her own television and movie production company.

1930s: Unemployment reaches as high as 25 percent of the total U.S. population as the effects of the Great Depression set in. A loaf of bread costs $.09.

1950s: The U.S. economy prospers after World War II, and there is only a 2 percent unemployment rate. A loaf of bread costs $. 14.

1990s: The U.S. economy enjoys another prosperous decade as the stock market rises and the country has an overall unemployment...