What is special about mark twain's realism

Mark Twain dealt largely with lower strata of society. Mark Twain's contribution to the development of realism and toAmerician literature as a whole was partly through his theories of local Colorism in American fiction,and partly through his colloquial style.
Mark Twain prefered to represent social life through portraitsof local places whici he knew best.He drew heavily from his own rich fund of knowledgeof people and places.He confinedhimself to the life with whichhe has familiar.By quoting from his own experince,Mark Twain managed to transform in to art the freedomand humor,in short,the finest elements of wester culture.