Final answer:
The question appears to be based on a misunderstanding or mix-up of historical figures and events. Stephen Foster was known for blending African and European musical traditions but there's no record of activities he performed within a year in Africa.
Step-by-step explanation:
The question "What did Foster do within a year in Africa?" does not accurately reflect the information provided about Stephen Foster or other individuals mentioned in the reference materials. Stephen Foster was an American songwriter who blended African and European musical traditions in the 19th century to create popular American folk and pop music, but there is no mention of him doing something specific within a year in Africa. Instead, we have information about different historical figures and events related to Africa.
For instance, Christian Hornberger, a missionary who took photographs in Africa, or the fight between Foreman and Ali in Zaire. Additionally, Leo Africanus wrote a detailed survey of Africa after being captured and baptized, and the controversial efforts at establishing an overseas empire by the US are mentioned which involved African Americans in military campaigns and the struggle against diseases like yellow fever.
Another example is Marcus Garvey's plans for African American migration to Liberia. Therefore, the question appears to be based on a misunderstanding or a mix-up of historical figures and events.