I am sure that others here have come across the word "mango" in
old cookbooks and seen that this does not refer to the tropical
fruit. I just ran across a possible explanation for how this term
came to be. William Woys Weaver says that "[i]n seventeenth
century England, stuffed tropical mangoes were imported from
India.... In an effort to reproduce [this], English cooks took to
'mangoing' all sorts of substitutes, from cucumbers to unripe
peaches. Americans, however, preferred baby muskmelons, or in
areas where they did not grow well, bell peppers." Indeed, what I
have seen almost always refers to pickled stuffed bell peppers.

--
Jean B.