This chapter treats the marketing of transatlantic passenger shipping companies from the post-Famine period to the emergence of amphibious aviation at the end of the Free State era. It explores the use of evolving advertising, marketing and public relations techniques, collectively commercial propaganda, in the USA on the transatlantic passenger shipping trade. It compares and contrasts the commercial propaganda of American shipping lines with that of their British and Irish counterparts to determine the degree to which American marketing techniques influenced domestic marketing, shaped consumer tastes and stimulated desire for an American life experience that was grounded in participatory civic consumerism. The chapter suggests that the reverse flow of knowledge and practices, stimulated by temporary and permanent reverse migration, and correspondence with Irish-America, led to the post-Famine modernisation of commercial promotional activity, with attractive communications from America copied by shipping lines and agents in the Irish market to create a domestic, Americanised form of marketing, more sophisticated and polished than previously seen.