In the 19th century, a heated dispute arose over the house sparrow and its introduction into North America. Elliot Coues and Thomas Mayo Brewer held opposing opinions on the matter which they defended their entire lives. 
Research:

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Glass, Chris. “The House Sparrow in Boston, Part I.” Boston Public Library Blog. 7/28/2022. https://www.bpl.org/blogs/post/the-house-sparrow-in-boston-part-i/
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Glass, Chris. “The House Sparrow in Boston, Part III.” Boston Public Library Blog. 7/28/2022. https://www.bpl.org/blogs/post/the-house-sparrow-in-boston-part-iii/
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Allen, J.A. “Biographical Memoir of Elliot Coues: 1842-1899.” Read before the National Academy of Sciences, April 1909. https://www.nasonline.org/publications/biographical-memoirs/memoir-pdfs/coues-elliott.pdf
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Coues, Dr. Elliott. “The Ineligibility of the European