Gregg,

I tried to identify L.W.M. a while back when I put that cartoon online in
a collection of Twain political cartoons.  The only person with those
initials listed in the index of Paul P. Somers, Jr., _Editorial Cartooning
and Caricature: A Reference Guide_ (Greenwood, 1998) is Lillian
Weckner Meissner.  She is mentioned in the text as being one of the
cartoonists included in an exhibit on "Women Practitioners of the
'Ungentlemanly Art'" at Ohio State University (1989).  The catalog for
the exhibit was published as _1989 Festival of Cartoon Art_, but I
haven't seen that yet.  I haven't been able to find anything else about
her.  It's very possible that her career started later.  There were not
many female cartoonists in 1900, and she's not mentioned in the
discussion of early cartoonists in Alice Sheppard's _Cartooning for
Suffrage_.

Ohio State University has a Cartoon Research Library and they could
probably provide information about her, but they charge for research
services:

http://www.lib.ohio-state.edu/cgaweb/research.htm

Jim Zwick