If you're a fan of Mark Twain, here's a little treat for you: I believe it's the only film ever made of him, shot by Thomas Edison in 1909, the year before Twain died. It shows him walking around his estate and playing cards with his daughters.
For Twain's advice on writing, and that of many other classic and modern writers, see my book, 'Your Creative Writing Masterclass," published by Nicholas Brealey and available from Amazon or your other favorite book seller.