George Washington's Secret Six: The Spy Ring That Saved America

How the Irish Saved Civilization: The Untold Story of Ireland's Heroic Role from the Fall of Rome to the Rise of Medieval Europe

The Johnstown Flood

Say Nothing: A True Story of Murder and Memory in Northern Ireland

The Great Bridge: The Epic Story of the Building of the Brooklyn Bridge

The Island at the Center of the World: The Epic Story of Dutch Manhattan and the Forgotten Colony that Shaped America

Sex Money Murder: A Story of Crack, Blood, and Betrayal

Mornings on Horseback

The Glorious Heresies: 'A big, brassy, sexy beast of a book' IRISH TIMES

Red Sky in Morning: author of the 2023 Booker Prize-Winning novel Prophet Song

The Philadelphia State Hospital at Byberry: A History of Misery and Medicine

The Crooked Branch

The Outside Boy

Murder, Inc.: The Mafia's Hit Men in New York City

The Padre: The True Story of the Irish Priest who Armed the IRA with Gaddafi's Money

The History of Ireland

Secret Child

Pain, Parties, Work: Sylvia Plath in New York, Summer 1953

Rediscovering God in America: Reflections on the Role of Faith in Our Nation's History and Future