The triumphal arch holds a very important place in the annals of Western architecture and urbanism. In Roman times it played a lofty honorific role, even though most Roman arches commemorated civic achievements and personages rather than military victories. The freestanding monumental arch was a syncretic creation, structurally derived from Etruscan gateways and decoratively enriched with Hellenistic architectural and sculptural forms. Its distinctive presence, which accommodated an astonishing variety in massing and detail, enriched towns and cities across the Roman empire, from Spain to Syria.
The monumental arch should be regarded as a universal entity—eminently appropriate, one would think, to a universal nation like these United States. The late, great historian of imperial Roman architecture, William L. MacDonald, noted how the arch corresponds to the classical concept of human proportions as delineated in Leonardo da Vinci’s Vitruvian Man, in which a male figure is inscribed within an overlapping circle and square. The impost or “springing” of the opening within the arch corresponds, MacDonald noted, to the Vitruvian Man’s arms extended directly outward, while the curvilinear opening itself corresponds to his arms sweeping upward. The arch’s geometry thus addresses us as embodied beings. You can’t get more universal than that.