Does anyone know if any Twain-related research has been done on consular cables in US archives? 

For example, at an Adelaide (Australia) function in Oct 1895, Twain was introduced by the American Consul Mr C. A Murphy.  This would not have been the first time Twain mixed company with US diplomats, abroad or at home.

Barb Schmidt has kindly directed me to this website: http://www.archives.gov/research/arc/

With a resource such as David Fears's "Mark Twain Day by Day" to hand, it might just be possible to identify diplomats who interacted with Twain in various capacities over the years. Twain’s political interests, views on copyright and other business ventures might conceivably have been the subject of consular interest.

The above website reports >>>

The diplomatic correspondence of the Department of State, 1785- 1906, is for the most part arranged in four main series of letters: instructions sent by the Department to U.S. diplomatic officers in foreign countries, despatches to the Department, Department of State notes to diplomatic representatives of foreign governments in the United States, and notes from such representatives to the Department. The correspondence in each of these four series of records is generally bound separately for each country. When these series are taken as a whole for any given country, they contain information on all phases of U.S. diplomatic relations with that country.
>>>

Read more here: http://www.archives.gov/research/foreign-policy/state-dept/finding-aids/inventory15-part1.pdf

Regards, 
Ron Hohenhaus
Brisbane, Australia
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