'telegraphic': "abbreviated or concise like a telegram," 1848

[Geoffrey Nunberg]

Now the certain effect of the Telegraph, as far as it has any
influence upon the language, (and who at the present day will dare to
estimate its possible influence in the future,) will be to introduce
a style of writing which shall be, first of all, brief. Brevity, it
is said, is the soul of wit; it is indeed the soul of all language,
grave or gay, for every purpose to which it can be applied, except
caricature. We never yet heard that tediousness was the soul of
anything in particular. The Telegraphic style, as we shall denominate
it, for the benefit of all future writers upon rhetoric, is also
terse, condensed, expressive, sparing of expletives and utterly
ignorant of synonyms.

Conrad Swackhamer, "Influence of the Telegraph upon Literature," The
United States Democratic Review, May 1848, pp 410-414,

The OED gives its earliest cite for this sense of the word from 1896.

Geoff Nunberg

------------------------------------------------------------
The American Dialect Society - http://www.americandialect.org