Where the influenza pandemic began is not precisely known. If you note the fuller quote from my article, I said: "Some concluded it started in China or European trenches. However, the CDC and other authoritative sources report that the influenza epidemic actually began in the US spreading to Europe as US troops deployed and later to Asia." There is a continuing debate on where this strain began. In the CDC report I cited and others, the first cases were reported in Kansas. The CDC article also mentions a rise in mortality rates in the US beginning in 1915 and 1916 which abated in 1917 which I took to imply that the flu was circulating in the US before 1918. The article could not conclude whether the 3 waves were a single strain or one of several, or one that mutated into an especially virulent form. https://wwwnc.cdc.gov/eid/article/12/1/05-0979_article#r21 National Geographic reported in 2014, the conclusions of historian Mark Humphries who has advanced the theory that Chinese workers spread influenza first in North America and later Europe. As with other theories, this one has some factual backing. However, the lack of samples from each wave of the disease makes it impossible to be certain of the place of origin. https://news.nationalgeographic.com/news/2014/01/140123-spanish-flu-1918-china-origins-pandemic-science-health/ Here is another article I referenced but did not include as a source that has a good discussion of the origins of the influenza outbreak. I thought the arguments favoring the US as the first source were the most convincing: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC340389/ I had other sources, most notably the book by John Barry who has written a recent and complete account: The Great Influenza: The Story of the Deadliest Pandemic in History. Barry wrote "In 1918, an influenza virus emerged-- probably in the United States-- that would spread around the world" on page 4 and he repeated that assertion later though it is not definitive. Barry wrote a summary of his book for Smithsonian.com based on his book which echoes US as a likely source of origin that you may be ale to access more easily: https://www.smithsonianmag.com/history/journal-plague-year-180965222/#JbHm5V61i7Q2dWeT.99 If you look this subject up on the internet, you can find some reports that cite other possible origins. The origin is only a detail, not the focus of the article. One of my favorites, which I could not work in without having to add a lot of extra verbiage is a claim that the 1918 influenza came from space (not aliens, a meteor). It's an interesting theory but seems to have been rejected by most experts. Here's the main proponent, Chandra Wickramasinghe (who is a real scientist as far as I can tell) in his own words. http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(03)13440-X/fulltext Thanks for reading my article and posting your comment. I hope this was not too lengthy of a response but I did a fair amount of research and I had previously heard about the space theory.