Dr. Mae C. Jemison, First African-American Woman in Space – GPN-2004-00020 (Photo credit: Wikipedia)

English: Astronauts Dr. N. Jan Davis (left) and Dr. Mae C. Jemison (right) are mission specialists on board the STS-47 mission. (Photo credit: Wikipedia)

English: Former president of Ghana Jerry Rawlings, speaking at the Oxford Law Faculty. (Photo credit: Wikipedia)

Official photographic portrait of US President Barack Obama (born 4 August 1961; assumed office 20 January 2009) (Photo credit: Wikipedia)

With his family by his side, Barack Obama is sworn in as the 44th president of the United States by Chief Justice of the United States John G. Roberts, Jr. in Washington, D.C., Jan. 20, 2009. More than 5,000 men and women in uniform are providing military ceremonial support to the presidential inauguration, a tradition dating back to George Washington’s 1789 inauguration. VIRIN: 090120-F-3961R-919 (Photo credit: Wikipedia)

Barack Obama and Michelle Obama (Photo credit: Wikipedia)

Harriet Tubman, full-length portrait, seated in chair, facing front, probably at her home in Auburn, New York (Photo credit: Wikipedia)

A map of four key locations in the life of Harriet Tubman (Photo credit: Wikipedia)

Harriet Tubman (Photo credit: Wikipedia)

Southern Rhodesia Africa 1953 Acacia (Photo credit: expom2uk)

Victoria Falls from the Zimbabwean side (Photo credit: Wikipedia)

Victoria Falls from the sky, September 2003 Photo by Vberger (Photo credit: Wikipedia)

Victoria Falls (Photo credit: Wikipedia)

English: Zimbabwe (orthographic projection) Español: Zimbabue (proyección ortográfica) (Photo credit: Wikipedia)

English: Flag of Zimbabwe Rhodesia between June, 1979 – April, 1980. (Photo credit: Wikipedia)

Tulsa-riot-fire (Photo credit: Wikipedia)

Little Africa on Fire. Tulsa Race Riot, June 1st, 1921 Apparently taken from the roof of the Hotel Tulsa on 3rd St. between Boston Ave. and Cincinnati Ave.. The first row of buildings is along 2nd St. The smoke cloud on the left (Cincinnati Ave. and the Frisco Tracks) is identified in the Tulsa Tribune version of this photo as being where the fire started. (Photo credit: Wikipedia)

Little Africa on fire. Tulsa Race Riot, June 1st, 1921 This photo was taken from on top of the Santa Fe Freight office at 1st St. and Elgin Ave., showing the fires on Archer towards Greenwood. The Goodner-Malone company (1 N. Frankfurt) building is in the center of the photo. (Photo credit: Wikipedia)

Map showing the location of the secessionist Republic of Biafra within Nigeria. (Photo credit: Wikipedia)

English: Flag of Biafra Igbo: Okoloto nke Biafra (Photo credit: Wikipedia)