The "Yellow Peril" emerged in the late 19th century, reflecting fears of East Asian immigration and cultural influence, leading to policies like the Chinese Exclusion Act of 1882. Similarly, the "Green Peril" describes fears of Islamic fundamentalism, especially post-Cold War, paralleling these anxieties.

"Greenback" is a slang term for the emergency paper currency issued by the U.S. during the American Civil War in the mid-1860s. Its distinctive green ink recognised it. Initially, the notes were used to finance the Civil War and were backed by the government. However, they were not backed by gold or silver, which led to fluctuations in value and inflation.