History of the United States Navy the Panama Canal, which was completed in 1914. The Great White Fleet required almost 50 coaling ships, and during the cruise most of the fleet's coal was purchased from the British, who could deny access to fuel during a military crisis as they did with Russia during the Russo-Japanese War. When United States agents discovered that the German merchant ship "Ypiranga" was carrying illegal arms to Mexico, President Wilson ordered the Navy to stop the ship from docking at the port of Veracruz. On 21 April 1914, a naval brigade of marines and sailors occupied Veracruz. A total of 55
Import-Export Clause a harbor and were distinct from charges imposed for pilotage or loading and unloading cargo. In "Clyde Mallory Lines v. Alabama", the Supreme Court explained that the prohibition on tonnage duties "was due to the desire of the framers to supplement [the Import-Export Clause] ... by forbidding a corresponding tax on the privilege of access by vessels to the ports of a state, and to their doubts whether the Commerce Clause would accomplish that purpose." The Tonnage Clause was also, like the Import-Export Clause, intended to prevent states with convenient ports from taxing goods destined to states which lacked good