That is freakin' awesome duuude - great family history! The Boston Public Library has some of the most amazing decorative art with John Singer Sargent murals on the walls and ceilings, and if your family had something to do with it I'm ever thankful because I always take the time to stare up at them like some lunatic lost at sea gazing at the stars: https://www.bpl.org/blogs/post/the-origins-of-a-masterwork/

And Mark Twain is an amazing connection, however doubtful or tentative... the duude was a network node of sorts and was connected to folks like John D. Rockefeller of Standard Oil fame... Twain was especially close to several of the top Standard Oil executives who basically bankrolled him.

You might know of the journalist Ida Tarbell who took down Rockefeller back in the day - well Twain introduced Tarbell to one of the top Standard Oil execs Henry Rogers - and that enabled her to write her famous McClure's articles and her. book on Std Oil that propeller her into history:

https://en.wikipedia.org/wiki/Ida_Tarbell

Very cool duuude! I'd love to hear more as you dig into your family's history.

SD