Twain's father purchased the property in 1839 but the date the house was built is unknown.  Sam was living there by the time he was eight years old.  The family lived there until 1853.

Bear Creek passes through southern Hannibal, about a half mile from Sam's boyhood home.  He learned to swim in Bear Creek and as with other boys ignored the ordinance against swimming within the city limits.  He saw two friends drown there and claimed to have nearly drowned there twice, himself.  See chapter 55 of Life on the Mississippi.

They reached Horta early on 21 (not 20) June. Like most of the other passengers, Clemens spent a busy day on shore and probably began this letter when he returned to the ship that evening. Continued rough seas delayed departure for Gibraltar until noon of 23 June.

SLC to Jane Lampton Clemens and Family, 21 and 29 June; 1, 3, and 5 July 1867, Azores, Portugal (UCCL 00139), n. 1. 

175.13 “Esmeralda” had just had a run] The principal town in the Esmeralda mining district was Aurora (claimed by both California and Nevada, until the resolution of the boundary dispute in the fall of 1863), which was located in the Sierra Nevada foothills about a hundred miles southeast of Carson City (see supplement B, map 3).

On January 22, 1865, Mark Twain went north from Jackass Hill, in nearby Tuolumne County, to Angel's Camp with Jim Gillis, who had a claim there. During their first week, heavy rains confined them to Tryon's Hotel; they spent the next three weeks prospecting with little success. Throughout this time -- especially during the rainy week -- Mark Twain exchanged yarns with locals, notably Ben Coon, and left with a notebook filled with story ideas. Chapter 61 of Roughing It briefly describes this period.

Twain's summer home...Quarry Farm is located in Elmira, New York. In 1869, Jervis Langdon purchased it as a vacation home for his family. When he died the following year, it was inherited by his eldest daughter, Susan Langdon Crane, Mark Twain's sister-in-law. Twain and his family summered there for more than twenty years. He wrote much of his work in an octagonal study built expressly for him, apart from the main house, in 1874. The study has since been moved to the Elmira College Old Campus in order to protect it from vandalism.

Mark Twain visited Africa on two separate journeys.  This, his first visit, he writes about in "The Innocents Abroad".  He actually visits the continent twice on this trip.  At its furthest point he visits Egypt.  Of course, in the world of fiction Tom, Huck and Jim take a balloon ride over the Sahara in "Tom Sawyer Abroad".  Many years later Mark Twain visits South Africa, as written about in "Following the Equator".

Fairhaven was first settled in 1659 as "Cushnea", the easternmost part of the town of Dartmouth.

Visited by Mark Twain in 1867 and in 1903. He first arrived June 29, 1867 and again October 17. He spent most of the first stop visiting Tangier, the second stop touring southern Spain. He stopped at Gibralter November 3,1903, with his family, enroute to Italy. (Mark Twain A to Z)