Ypiranga incident Ypiranga incident The "Ypiranga" Incident occurred on April 21, 1914, at the port of Veracruz in Mexico. The SS "Ypiranga" was a German steamer that was commissioned to transport arms and munitions to the Mexican federal government under Victoriano Huerta. The United States had placed Mexico under an arms embargo to stifle the flow of weaponry to the war-torn state, then in the throes of civil war, forcing Huerta's government to look to Europe for armaments. "Ypiranga" tried to enter the harbor at Veracruz to unload on the first day of the US occupation but was detained by US troops
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