March 17 Sunday – Sam was asked to make a few remarks to a Sunday school, at his sister Pamela’s church. Sam told the “Jumping Frog” story, but could not supply a moral from the story, so “let it slide” [MTL 2: 19 n2; Sanborn 322].
Alta California printed Sam’s article “UNDER WAY AGAIN” which Sam dated Jan. 1 [Schmidt].
Camfield lists this as “Letter from Mark Twain” Number VI [bibliog.]. Sam’s article “A Curtain Lecture Concerning Skating” ran in the New York Sunday Mercury [Camfield bibliog.].

March 16 Saturday – Alta California printed Sam’s article “THE TWIN MOUNTAINS” which Sam dated New Year’s Day [Schmidt]. 

Camfield lists this as “Letter from Mark Twain” Number V [bibliog.].

March 15 Friday – Alta California printed Sam’s article “THE FIRST DEATH” which Sam had dated from December 24 to January 1 [Schmidt]. 

Camfield lists this as “Letter from Mark Twain” Number IV [bibliog.]. Sam’s article “Iniquitous Crusade Against’ Man’s Regal Birthright Must Be Crushed” ran in the Missouri Democrat [Camfield bibliog.].

March 14 Thursday – The first of five letters from Hawaii, reprints of five early Sacramento Union letters with “a few minor omissions” ran in the New York Weekly. Dated Mar. 18, 1866, beginning: “We arrived here to-day at noon…” this first article omitted “the short anecdote of Brown’s mistaking a cake of soap for a ‘curious foreign dish’” [The Twainian, Mar. 1944 p2-3]. These letters are notable for their promotional value to Sam’s upcoming New York lecture.

March 13 Wednesday – Sam’s “Volley from the Down-Trodden” ran in the Missouri Democrat [Camfield bibliog.].

March 12, 13 and 15 Friday – Three articles: “Female Suffrage: Views of Mark Twain” first appeared in the St. Louis Missouri Democrat on these days [Budd, “Collected” 1007; MTTMB 287n1].
These were reprinted in the Alta California April 10, 28, and May 11. From two of Sam’s letters on suffrage:

March 7 Thursday – The New York Weekly announced it would print (re-print) a series of Mark Twain’s “inimitable papers.” The weekly reprinted five of Sandwich Islands Letters to the Union, but without mention of the prior publication [MTL 2: 12n3].

March 6 Wednesday – Artemus Ward (Charles Farrar Browne) died of tuberculosis after his last performance on Jan. 23 in London. Ward was 33. He was interred near London but his body was later shipped back to America to be buried at Waterford, Maine. It arrived in New York in May, when Sam noted the event in one of his Alta letters.

March 5 Tuesday – The New York Saturday Evening Express published “Barnum’s First Speech in Congress,” by Mark Twain, on page one [MTL 2: 11-12n3]. Sam arrived in St. Louis at midnight after sitting up for two nights in coach due to full sleeping cars. Sam was returning home after six years and four months. He went directly to his sister Pamela’s house at 12 Chestnut Street, where he “sat up till breakfast time, talking and telling lies.” Sam’s niece, Annie Moffett, was almost fifteen and his namesake nephew, Sammy, was six [Sanborn 320-21; MTL 2: 18n1].

March 3 Sunday – On a snowy night Sam left New York for St. Louis on the 8 o’clock New Jersey Central. It was a 52-hour rail connection. On the same day the New York Sunday Mercury published “The Winner of the Medal,” by “that prince of humorous sightseers, Mark Twain, whose contributions to California light-literature has gained him a front-rank position among the sparkling wits of the Land of Gold” [MTL 2: 11n3, 18n1].