the Chuckwagon, evolved from a US Army surplus Studebaker wagon, invented by Charles Goodnight, 1866

Above image from http://petticoatsandpistols.com/2009/03/06/stacey-kayne-chuckwagon-more-than-a-cowboys-meal-on-wheels/  where you will find a brief article about cowboy cattle drives and the chuckwagon, but for a very indepth article about the inventor and the chuckwagon, http://wildwesthistory.blogspot.com/2012/08/charles-goodnight-and-his-famous.html#comment-form

above poster is not very good resolution because they are trying to sell them, but can be found at http://www.midwestbuggy.com/images/sale_wagonposter.jpg