Looking for my ancestors

My great-great grandfather Thomas Downey was Married to Alice Murphy - I believe they were married in Ireland before they left for the United States around 1850 and they went to New York and lived there for a few years before they moved to Chicago- Their children were James, Mary ( possibly born in New york) and John, Chalres J,, Alice and Rose Mary ( who became Rose Ryan, married in Chicago to Thmas C Ryan)

On Charle's death certificate it lists his father's birth place as Kerry ( spelled wrong -Carry- probaly misspelled by an American who wasn't irish!) If this information sounds familiar to anyone, I would love to hear from you- thank you- Andrea Pulido