Sorry if I'm making too many threads. I was reading about immigration to the US in the 19th century, and came across the story of Chinese immigration to the US. It's common knowledge that the vast majority of Chinese immigrants initially came from Guangdong.
What I can't figure out is why. So, anyone who knows their 19th century Chinese history, why did all the immigrants come from that particular region of China, instead of from all over the country?