This article examines shipping and goods traffic trends and the infrastructural development of the port of Naples from 1860, when the city became part of the Italian State, to 1960. The Author analyses both the composition of cargo flows over that time span and the port’s functional role within the framework of the backward economic system of Southern Italy. At the end of the 19th century, Naples became the country’s leading migration port: passenger traffic trend is thus deeply reviewed as well as the problem of expanding and modernising the harbour’s infrastructures. At the fall of the Bourbon kingdom (1860), the port of Naples presented very poor operational conditions and important works were urgently needed to meet steam shipping requirements. The upgrading of the port’s berthing structures and commercial facilities was achieved only during the time span 1925-1933, within the framework of a comprehensive town planning scheme. Cause and an effect of that great delay was the weakening of the local merchant class whose economic attitudes are carefully considered by the Author.