According to Ron Powers, today, February 3 (1863), is the date of record for
the first item printed over the signature Mark Twain, in a dispatch (letter)
from Carson City, Nevada to the Territorial Enterprise in Virginia City.
Soon after, he moved to San Francisco, and continued to use the pen name,
but not for straight news in The Call.

SO HAPPY BIRTHDAY, MARK TWAIN.

"I feel very much as if I had just awakened out of a long sleep" was the
lead sentence. Glad he kept his dreams and memories.

Richard R, San Francisco