There might be a connection. My great grandfather was Thomas Dunnigan (spelled Donegan on Birth Cert.)He was born on January 23, 1864 on a farm in Pendelton, Niagra Co., NY near Buffalo. His parents were Henry Donegan and Johanna O'Hearne Donegan. I wonder because they lived so close were are related. What do you know? His family came to NY to work the Locks in the canal.