In a March letter to Albany Fonblanque, a friend and highly regarded newspaper editor in England, Dickens painted a vivid image about the “prevalence of spit-boxes” and related unsavory issues:“They are everywhere. In hospitals, prisons, watch-houses, and courts of law – on the bench, in the witness box, in the jury box, and in the galley; in the stage coach, the steam boat, the rail road car, the hotel, the hall of a private gentleman, and the chamber of Congress; where every two men have one of these conveniences between them – and very unnecessarily, for they flood the carpet, while they talk to you. Of all things in this country, this practice is to me the most insufferable. I can bear anything but filth. I would be content even to live in an atmosphere of spit, if they would but spit clean; but when every man ejects from his mouth that odious, most disgusting, compound of saliva and tobacco, I vow that my stomach revolts, and I cannot endure it. The marble stairs and passages of every handsome public building are polluted with these abominable stains; they are squirted about the base of every column that supports the roof; and they make the floors brown, despite the printed entreaty that visitors will not disfigure them with ‘tobacco spittle.’ It is the most sickening, beastly, and abominable custom that civilization ever saw.”
This letter and others containing Dickens' impressions of American life in that period are published in The Letters of Charles Dickens - Vol. 3, 1836-1870. He also wrote about his American visit in a book titled American Notes for General Circulation (Cambridge Library Collection - North American History). Both of these sources provide first-person insight, based on an outsider's view of everyday life, that you don't often find recorded.