Mt. Carmel was founded in 1900; Carmel of Mundelein about 60 years later.
Mt Carmel is generally referred to as "Carmel" by students, alums and practically everyone else on the South Side or in the catholic League.
When Carmel in Mundelein was founded, the priests figured it was so far away that there would never be any confusion.
Wrong!
As the,Edgy board grew and expanded, there were far fewer Mundelein guys than those from Chicago. As a result, if referring to the school in the north suburbs, the writer ususally said Carmel (M). This was a point of contention for their people who thought we should add Mount whenever we referred to our school.
In any event, Carmel (M)'s football fortunes have declned over the past few years and the school is seldom mentioned, here. The problem seemed to solve itself.
Note that Carmel (M) is co-ed while Mt Carmel is all boys. Mundelein's colors are brown and gold. Mine are brown and white.
Brown is a significant color in the Carmelite tradition.