Lots of research, lots of letters, and lots of people have culminated in the beta version of the Mark Twain Project Online, which is now available at www.marktwainproject.org . At the moment this site contains more than 2300 letters written between 1853 and 1880, but eventually will contain almost 10,000 letters and eventually the most complete catalog of Twain’s writings available.
But you’ve got to start somewhere. If you start at the front page here you’ll find there are several separate sections, including a user’s guide, a place to organize Twain-citation, and a writings section (which is currently under construction.) The big attraction at the moment is the letters, of course. You can browse by year, or search by keyword and topic. It looks like the letters available are about half annotated, but you can view all of them annotated or not.
I did a search for sugar. I got 24 results presented in a table that included date, writer, addressee, place of origin, and volume. You have the choice of looking at text or details. The details are notes about the letter and citation information. The text, as you might imagine, shows the text of the letter and sometimes annotation and notes written about the letter. The letters vary a lot as to their content — I noticed that a lot of the time, my search keyword was in the annotation and not in the letter itself.
The infrastructure for what WILL be here is so extensive it makes what IS here look a bit thin. But don’t be fooled — this makes for lot of good browsing. Worth a look.