Hello kaligirl,
I too could find no record of Thomas's birth.
He had eight siblings: Mary (born 29/03/1870), Bridget (born 01/03/1875), Anne (born 30/06/1876), Christoper (born 09/08/1878), William (born 01/02/1883 died 11/07/1911), Catherine (born 13/02/1885), Pat (born 25/08/1886) and Ellen (born 01/05/1888).
His parents were Patrick Halpin and Bridget Heslin. I could find no record of Patrick's birth or baptism. He died on 27/12/1905. Bridget was baptised on 02/04/1847 and died on 04/11/1929. They were married in Collinstown, Westmeath on 21/01/1869.