A century after its appearance, the pandemic that killed in 1918 tens of mil-lions of people is still unjustly called Spanish Flu. To end this unfair allocation, it is necessary to show how this pandemic emerged in the United States. And to discover that the most deadly virus in History did not begin its expansion in 1918, but in 1917. Finally, it is important to know why the United States Army played a key role in infecting the world with the American Flu, and how this role was hidden by giving the adjective Spanish to the influenza.