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:

SYMHC Classics: Nelson Pill Hearings
38:25

Behind the Scenes Minis: Alaska and Contraceptives
28:17

The IUD: A History
44:41