Early "jeans" from Levi Strauss & Co, in "duck", from the American History Museum/Smithsonian, c. 1873-96.
This must be the "yellow" that Twain talks about here, don't you think?
Except--not brand name, did you catch that Twain specifically wrote homespun? Levi's patented "jeans" in 1873, the same year The Gilded Age was first published. I wonder what portion of the market Levi's held at that time, and what it really meant to wear homespun jeans. Were Levi's patented version famous enough for these men to be wearing intentionally copied work pants?
The Smithsonian website suggests denim wasn't used by LS&Co. until the 1890s; do you think Twain's men were wearing denim or blue duck? But still called "jeans"....so interesting!
Homespun reminds of itchy sweaters and ugly crochet now, I think, but in costume history I most strongly associate it with American protest of British imports when were still only a colony. And, of course, the dense but awesome book by Laurel Thatcher Ulrich. Check it out, especially if you are interested in New England clothing/textile history like yours truly.