Where did Darjeeling tea come from?

In my last post I talked about the two places where Camellia sinensis originated, and quickly admitted that I didn't know the origin of Darjeeling tea. Seems like a good place to continue, doesn't it?

So I did the barest minimum of research, and happened upon this site:

http://www1.american.edu/ted/darjeeling.htm

Almost seems like this was a lark by the fellow named Campbell who was a civil surgeon (what is that exactly?), but then it says that the government had already elected to set up tea gardens here. In the middle of the nineteenth century, this mountainous region at the foot of the Himalayas went from having no tea plantations to being practically overrun by them.

What I still don't understand is where the strain of tea came from. Did the earliest tea planters in Darjeeling simply plant tea from Assam, and is the light, delicious, floral result merely because of the soil and spirit of Darjeeling?

My intention was to not only search Wikipedia, but then at the bottom of the above-mentioned page, it directed me back to Wikipedia.

Will continue to research the origins of Darjeeling and let you know my results as I find them.