With Containerization starting in the 1960s a new port was built between New Orleans and Barton Rouge called "The Port of South Louisiana". It is now the largest port by volume in the United States. Houston is #2, New York City is #3. The largest exporter is South Louisiana, the largest Importer is Houston Texas (Which along with other Texas ports does a lot of imports of Mexican and Venezuela oil for refining and exports of the refined oil back to those countries). The largest port on the West Coast is Long Beach (#5 total), followed by Los Angles (#14 total), Port of Portland at #26, and Tacoma Washington at #30 total, Port of Richmond California at 33, Port of Seattle #37, Anacortes, Washington at #43, Kalamar Washington at #53, Vancouver Washington at 69, Longview Washington at 79, Port of San Diego at 99 and other even smaller ports. Please note the volume of the west coast comes no where near the volume of the Gulf Coast or even New York City itself.
My point is the good are imported at the various West Coast Ports and then shipped to Louisiana for export. Some are exported via other Gulf Coast ports and east coast ports. Given the price difference shipping to the port of Louisiana and reloading there then shipping the good by rail up to New York City to be refined in New Jersey Refineries, all of this oil imports inflate the numbers of both the Gulf coast ports and New York City imports.
List of US ports:
http://en.wikipedia.org/wiki/List_of_ports_in_the_United_StatesNew York City is still the number one port in the US (And Pittsburgh is #3, by tonnage, but its shipping is barge traffic on the rivers NOT imports or exports) but New Orleans is #2 (And does Not Include Barton Rouge which, while up river of New Orleans, is still a port). Mobile Bay is still a huge port as is Houston and Galveston Texas. Each of these ports are viewed as independent of each other and thus while their total tonnage of ALL of the ports from Mobile Bay to Houston may be larger then New York City it is divided between at least six different ports while New York City area only has to worry about the much smaller ports in Northern New Jersey.