I am also interested in McMahons from Ennis but probably a generation earlier.
My gg-grandparents were Steven McMahon and Nancy Ann Liddy from Ennis, Co. Clare. They were born in about 1806 and 1809. He came to the United States in 1846; and she came in 1850 with their 2 children (Terese Mary,~1839; and Michael, ~1842), settling in Collinsville, CT (the ax factory). The only other information is the oral history that he worked for the gas company and she had a milinery shop in Ennis. So far, I have found no record of them or where they might have been born.