Complex sentence: The McAleenan brothers from the nearby townsland of Ballymaginaghy were working in Dublin during 1887 and whilst there met Maurice Davin and Michael Cusack, early pioneers of the Gaelic Athletic Association (GAA).
Split into simpler sentences: The McAleenan brothers from nearby Ballymaginaghy were working in Dublin during 1887. While there, they met Maurice Davin and Michael Cusack, early pioneers of the Gaelic Athletic Association (GAA).