In 1955, at the age of thirty-two, he published his first book, Shipwreck & Empire: Being an Account of Portuguese Maritime Disasters in a Century of Decline, through Harvard University Press. This work, while focusing on Portuguese maritime history during the 16th and 17th centuries, had a more literary orientation. Duffy’s interest in contemporary Portuguese colonial history emerged—or at least solidified—after an extended visit to Angola and Mozambique in 1955 and 1956. During this visit, James Duffy gained firsthand experience of the Portuguese colonial system, particularly the economic, social, and political subjugation of African populations. His direct encounters with the harsh realities of Portuguese colonial exploitation—especially the violations of fundamental rights suffered by the black population subjected to the Indigenato system and legally obligated to perform forced labour—led him to adopt a critical stance. He became an outspoken critic, denouncing the injustices and inequities inherent in the Portuguese colonial regime.

In this context, Duffy emerged as one of the foremost critics of Portuguese colonialism within North American academia. Through his books and writings, he vehemently opposed and exposed Portugal's policies of discrimination and repression against the indigenous populations of Angola, Guinea-Bissau, and Mozambique. For instance, in 1962, at a programme organised in New York at the invitation of the Carnegie Foundation, Duffy candidly presented his criticisms and denunciations of Portuguese colonialism in Africa (James Duffy, Portugal’s African Territories: Present Realities , 1962).

Despite his overt anti-colonial stance, Duffy was a meticulous and skilled historian, producing several significant works on Portuguese colonialism in Africa. In 1959, he published Portuguese Africa through Harvard University Press, a project sponsored by the Ford Foundation. A few years later, in 1962, he authored Portugal in Africa, published by Penguin Books. This work, which has been reissued multiple times, includes an editorial by Ronald Segal focusing on the theme of "illiberal colonial policies," setting the tone for the critical content within. In these two books, James Duffy offered a critical and historiographically grounded assessment of the Portuguese colonial presence in Angola and Mozambique, spanning from the 16th century to the 1950s. Rejecting myths and politically constructed "fantasies" about Portuguese colonialism, he presented a contextualised historical analysis of Portugal’s so-called "colonising mission”—often referred to as a "civilising mission”—in Africa. Duffy examined a broad range of issues, not just political but also economic, social, and cultural. These included indigenous policy, white settlement, the economic, social, and cultural development of African populations, and the exploitation of natural resources in territories under Portuguese administration. In his overall evaluation, Duffy argued that Portugal had not been "successful" in improving the living conditions of the colonised populations, questioning whether such improvement was ever the genuine aim of Portugal's "colonising mission." While Duffy acknowledged Portugal's claims of racial tolerance, particularly when compared to more overtly segregationist regimes like apartheid South Africa, he concluded that Portugal left the majority of the African population in poverty and ignorance. They were subjected to continuous exploitation, particularly in the realm of forced labour.

1 | 2 | 3 | 4 | (Pdf)