Complex sentence: The Barbary Coast was an outgrowth of Sydney-Town, the area at the foot of Broadway and Pacific Street formerly inhabited by the Sydney Ducks, though the area was already a hotbed of prostitution and vice by the time the Australian immigrants arrived.
Split into simpler sentences: The Barbary Coast was an outgrowth of Sydney-Town, the area at the foot of Broadway and Pacific Street formerly inhabited by the Australian immigrants known as Sydney Ducks. The area was already a hotbed of prostitution and vice by the time the Australian immigrants arrived.