The enormous concentration of traffic upon a few large cities confirms the paramount importance of the Atlantic area (London, Liverpool, Cardiff, and New York) as well as of specific poles such as Hamburg and Buenos Aires, the latter being at the time a growing rival of European capitals. Other cities stand out less by their traffic than by their important share of steamer traffic, among which Antwerp, Bombay, Baltimore, and New Orleans. Asia is the region outside Europe hosting the largest number of cities specialized in steamer traffic.
For more information on data and further analyses (in French):
http://www.cnrs.fr/inshs/recherche/reseau-maritime-mondial.htm

César Ducruet