It is an all time consensus among literary critics that the U.S.A. trilogy is John Dos Passos`` magnum opus. Indeed, the trilogy is a magnum opus not only for his atypical career as a professional novelist, but also for modernism itself as a whole. Especially with its textual architectonic, which employs a variety of the artistic styles and devices of modernism such as modernist painting, imagist poetry, and cinematography, U.S.A. is designed to portray American capitalism of the first three decades of 20th century. At the same time, the trilogy also articulates the author``s message of political radicalism. With all these multidimensional aspects of the U.S.A. trilogy, this paper aims to investigate the dialectical scheme of textual architectonic, by which the novel presents successfully the whole, yet detailed aspects of American capitalism. Therefore, this paper will explore the dialectical architectonics of U.S.A. broadly by using some dialectical procedures of such thinkers as Karl Marx and Louis Althusser. Though not a traditional dialectician, G. Deleuze also gives us helping hands in understanding the dialectical politics of U.S.A. with his theory of the modern cinematography, especially his analysis on the montage techniques. K. Marx clarifies the dialectic as a way of thinking in Grundrisse that dialectical thinking moves forward from the abstract to the concrete in order to understand a whole as “a rich totality of many determinations and relations.” In terms of Louis Althusser``s dialectical logic, the dialectical practice progresses from the abstract concept, and then it reaches the concrete realities of “Generality III” with the mediation of the scientific theoretical operations. The U.S.A. trilogy follows faithfully this procedure of dialectical practice in order to present a literary portrait of American capitalism. More interestingly, the four unique narrative modes of U.S.A. interact dynamically as narrative montages, thereby forming a dialectical quartet of montage in portraying the whole yet dynamic landscape of modern American capitalism. Thus G. Deleuze``s argument on the montage practice of modern cinematography can shed light on the dialectical scheme of the U.S.A trilogy.