Why the 'Spanish Flu' wasn't Spanish

The 1918 flu pandemic got its name only because Spain, neutral in the First World War, had no wartime press censorship — so its newspapers freely reported the outbreak while other nations suppressed the news. Its actual geographic origin remains scientifically undetermined, with the United States, France and China all proposed as candidates.

— Standard historical and epidemiological accounts, Spanish flu — 1918–1919 pandemic