And 165 years after his death the sharp tongue of O'Connell, a formidable political leader, still riles those who are passionate about speaking Irish.
"It was unfortunate that historical figures compounded the colonist idea. What O'Connell said didn't do the language any good," admits Thomas Maguire, a fluent Irish-speaker.
The Sinn Fein councillor from Enniskillen is a member of Sruth an hÉirne, an Irish-speaking group that was set up in 2005 and has since flourished into something very special indeed.
"Why is it called Sruth an hÉirne? Because the name means the stream of the Erne. We want the language to stream, to flow. We are not doing it to show off and it certainly isn't being done to confront anyone. It is to try and make Irish as naturally as possible. There is a desire to learn it."
The group meets every Wednesday night at Blakes of the Hollow, one of the town's oldest pubs, where they discuss life and language over a few pints. But don't be fooled into thinking this Irish language group is confined to the pubs - or the past - because that would be "missing the point".
"This isn't about sitting around like people did in the old days and speaking in Irish. This isn't about going to a farmer's house in the evening and sitting around the fire. That type of image is wrong. The significance of the old pub isn't how old it is. The significance is we are getting the Irish language out there to the centre of the town. We are not trying to do this to be nostalgic and we are not trying to promote this as a nostalgic language either. It is a social event," he said.
The emphasis across Ireland, North and South, is that the language is alive, says Mr Maguire.
"It is a vibrant language. We aren't looking back at it, we are looking forward, especially with the blossoming of all the little Gaels clubs around the county. It is useful for young people because it covers all aspects of life. Take a dander around the internet and you can do anything in Irish; use Facebook, read articles on Wikipedia."
Mr Maguire says looking ahead to the future and encouraging young people to get involved is important for the group.
"There is an onus on us, the older guys, to create an Irish-speaking community," he says, before adding: "It is not being done for tokenism but to promote a very rich culture".
He recalls sitting in a local pub and speaking to a young man for 45 minutes in Irish.
"There wasn't one bit of English spoken in that time. On another occasion I remember standing on the steps of the Townhall, too, and someone went past and I engaged with them in Irish. If you want to have a conversation -- two people is enough. That's our group's motto," he added.
Mr Maguire says he would prefer if Irish didn't create an impact in Fermanagh, but that others acknowledged that many people of all backgrounds speak it.