The Cotter/Leahy combination is unusual. I have a great grandfather, Francis Cotter as well as one by the name of David Leahy. According to annecdotal information, they all came from the area around Abbeyfeale, County Limerick and ended up in Tiffin OH. Francis was born 1808 and Davlid 1800. My grandfather, Patrick Nelson Cotter married Katherine Leahy. My first record of the Cotter family is in Paris, Ky where Francis applied for citizenship. Whe lived in Lexington Ky before citizenship was granted in 1944. He married Mary Murphy in Lexington, had one child while there Ellen Cecilia. Sometime after 1844 they moved to Tiffin OH
Hope you find this interesting.