Galveston Bay is the second-busiest port in the nation by overall tonnage. Other major ports utilizing the bay include the Port of Texas City and the Port of Galveston. With its diverse marine life, Galveston Bay also produces more seafood than any bay in the nation except the Chesapeake. The Gulf Coast gained its present configuration during the most recent glacial period approximately 18 ka (thousands of years ago). Low global sea levels allowed the Texas mainland to extend significantly further south than it is presently, and the Trinity River had carved a deep canyon through present-day Bolivar Roads on its way
Port of Galveston island's grade. As a result, the port was now considered a deep-water port and was able to handle larger ships. By the time World War I began, Galveston "was the leading cotton port in the world, the third largest exporter of wheat, and an important sugar import center." The port also became a major immigration center, with almost 50,000 people entering the country between 1906 and 1914. In March 1920 local longshoreman called for a strike, seeking a wage increase and recognition of their union, the International Longshoreman's Association. Some of the port traffic was diverted to the Port of