I suggest people interested get a hold of this book by David Kennedy.
His 2003 thesis on the split is available here.
PDF | On Jun 1, 2003, David Kennedy published The Split of Everton Football Club, 1892: The Creation of Distinct Patterns of Boardroom Formation at Everton and Liverpool Football Club Companies | Find, read and cite all the research you need on ResearchGate
www.researchgate.net
It is a fascinating socio-historic analysis of the Club which had a majority of liberal minded, tolerant directors, and a rump of bigots who we left behind in 1892.
I know a Dub who is a red who was over for a match a few years ago. His rs jersey got soaked from heavy rain the morning of the match, so he wore a ROI jersey to the pit.
He was shocked at the sectarian abuse he received from his fellow so-called supporters.
Still a red mind you, but there was certainly a hard core orange element on the kop. I don't know if that is still the case.
Everton thankfully have always opened their doors to welcome players from all religions although we have to admit that we had a poor record regarding non-white players right into the 80s.
The wave of ROI immigrants to Merseyside in the 40s 50s and 60s were only going to choose one club - the one that had Farrell, Eglinton, Donovan, Corr, Meagan, O'Neill, Carey etc while the rs had none.