Mudie's Select Library was a major nineteenth-century literary institution. Substantially larger than its competitors, the library leveraged regional and global distribution networks and close commercial ties with publishers which allowed it to maintain a key position within the British publishing industry. In its heyday, it was widely believed that novelists and publishers were required to conform to aesthetic, moral and formal standards established by Mudie's, or risk the rejection and consequent failure of their books. However, the lack of a comprehensive study of the library's holdings leaves open questions about what the library actually stocked, and to what extent the library could determine a novel's fate. This Element describes a data analysis of a collection of Mudie's catalogues spanning eighty years, in order to reassess understandings of the library's role in the nineteenth-century publishing industry. This title is also available as Open Access on Cambridge Core.