Drawing on British and League of Nations archives and on petitions, diaries, letters, and newspapers in Palestine, Israel, and different Latin American countries in the 1920s, this paper explores how new forms of Palestinian self-understanding and identification, both territorial and diasporic, were molded through complex inter-communal and transnational communication within the context of emerging legal and political world orders. The paper examines the ways in which Palestinian immigrants - who had started leaving their homes in the late 19th century along with their Levantine neighbors for various reasons - came to self-identify in light of new political boundaries and citizenship legislation promulgated by the British-controlled Government of Palestine starting in the early 1920s. While this legislation would ultimately deny thousands of Arab Palestinians living in Latin American countries the right to return to their homeland as citizens, the diaspora it created nonetheless came to play a role in the development of a new and distinct identity among Palestinian Arabs in Palestine and abroad. This paper poses the following questions: to what extent and in which ways was this Palestinian diaspora connected to Palestine and Palestinians in Palestine? How did this connection change from Ottoman to British rule, and why did so many of the immigrants wish to return to Palestine in the aftermath of the Ottoman defeat? Moreover, what did these Palestinians abroad communicate to their relatives in Palestine in the letters and various correspondences from this period? What were Palestinians in Palestine saying in return? Which issues were important to these people as a community that now faced a new political, social, and legal status? In addition to these questions, this project aims to contribute to the expanding body of literature that adds complexity and nuance to the emergence and development of Palestinian nationalist consciousness in the aftermath of the First World War. It does so while paying particular attention to the persistence of the language of the right of return among Palestinians within Palestine and across this early diaspora in the many petitions and letters submitted to British and Arab offices in London and Jerusalem. This paper will thus highlight how the emergence of new political, legal, and social boundaries - both literal and figurative – following the institutionalization of the British Mandate impacted communal and personal modes of self-understanding and identification for people who would come to identify themselves one way or the other, as Palestinians worldwide.