Final answer:
The provided information does not specify a year when Stephen Foster traveled to Africa, as it does not mention him doing so at all. His musical influences came from his experiences in Pittsburgh, not from personal travels.
Step-by-step explanation:
The question related to when Foster traveled to Africa appears to be a confusion. The provided information speaks about Stephen Foster, who was known for blending African and European musical traditions, but does not specifically mention him traveling to Africa. It seems there is no record of Stephen Foster traveling to Africa within the given reference materials. According to the information, Foster did experience African music influences, particularly from African American boatmen in Pittsburgh.
However, his compositions were inspired by the cultural environment of his home city and the African and European musical traditions he encountered there, not by personal travels to Africa. To provide some context on the era, Stephen Foster lived from 1826 to 1864, and his music was, indeed, greatly influenced by African American music.