As historiographer of the American Irish Historical Society, County Cork-born Michael J. O'Brien focused on Irish contributions to colonial America. In 1919, as the Irish War of Independence heated up, he published A Hidden Phase of American History: Ireland’s Part in America’s Struggle for Liberty. The book was soon deployed to help make the case for why America should support Ireland's struggle for liberty. When US Senator John Sharp Williams, a Mississippi Democrat, attacked the Irish in a widely reported speech, O'Brien was drafted to issue the reply.

Presented by journalist Mark Holan, who wrote the Dictionary of Irish Biography entry about O' Brien.