Conversation so far:
When did Alexander Graham Bell begin his early work on the telephone?
Returning to Boston in fall 1873, Alexander Graham Bell made a fateful decision to concentrate on his experiments in sound.
What led to Alexander Graham Bell's discovery of the telephone?
Alexander Graham Bell had long been fascinated by the idea of transmitting speech, and by 1875 had come up with a simple receiver that could turn electricity into sound.

Question: What was happening at the time of his discovery?
Self-contained rewrite: What was happening at the time of Alexander Graham Bell's discovery?