These three names and others of a similar sound such as Donnellan and Donlon are sometimes confused, as spelling variations have occurred among emigrant families. They are, however, totally distinct, and indeed both the McDonnells and O'Donnells are made up of several distinct septs. The main branch of the O'Donnells, based in Donegal, is the most eminent of the Gaelic families, leading back to Niall of the Nine Hostages, but owing their name to one Domhnaill. Another branch was from Thomond (Limerick and Clare), and a third from Galway/Roscommon. The Donnelly or O'Donnelly family are also from the same stock as the O'Donnells in that they too are descendants of Niall of the Nine Hostages and are originally from what is now County Tyrone. The McDonnell family are more complicated, having several separate roots, one of which is the McDonnells of Antrim who were a gallowglass (mercenary soldier) family. The roots of the other McDonnell families are in Donegal and Clare. Because of the frequent omission of the O and Mac from Gaelic names, it is sometimes difficult to distinguish the origin of a person named Donnell. Among the prominent Donnells whose specific kinship is difficult to determine is James C. Donnell (1853-1927) who was brought to the U.S. at age two and became a crude-oil hauler in Titusville, Pennsylvania, later rising to become a vice president with Standard Oil, and later president of Ohio Oil. He was a classic oilman who, even at the height of his executive career, liked to work at the wellhead. He is estimated to have drilled 42,000 wells during his career and at his death was one of the last oil giants. Among the prominent Donnellys is Ignatius Donnelly (1831-1901), an entrepreneur of Philadelphia who went to Minnesota to found a town and, on its failure, farmed the site instead. He became a Republican politician and lieutenant governor of the state, and later a congressman in 1863-69. Perhaps the most famous of the O'Donnells historically was Red Hugh O'Donnell (1575-1608) who, at age 18, was kidnapped and imprisoned by the English Deputy in Ireland who feared the power of the clan. In 1591, along with the famous Hugh O'Neill, he escaped, and the following year was inaugurated as Chief of the O'Donnells. He joined with O'Neill and the other Ulster chieftains in the Nine Years War against the English which was finally lost at the Battle of Kinsale. Hugh O'Donnell was sent to Spain to enlist further help and died there, apparently from poison administered by an English spy. Of the Donegal O'Donnells, there was Frank Hugh O'Donnell (1848-1916), the politician and journalist who left the Parliamentary Party due to his opposition to its leader Parnell, but later wrote a major history of the party. Possibly the most prominent O'Donnell in Ireland at the moment is the very popular Donegal-born singer Daniel O'Donnell. In the U.S., prominent O'Donnells include chat-show host, author and actress Rosie O'Donnell and actor Chris O'Donnell whose credits include Batman Forever, Circle of Friends and , In Love and War among many others. The O'Donnell, McDonnell and Donnelly families were prominent in the American struggle for independence. There were 155 Donnellys, 139 McDonnells and 36 O'Donnells in the American Revolutionary Army. The list of soldiers in the war also illustrates the range of spelling variations that occur in the U.S. The list includes Ensign John O'Connell of Washington County Militia, Pennsylvania; Captain Nathaniel Donnell of Steven New York Artillery; Colonel Andrew Donnally of Botecourt County Militia, Virginia; Lieutenant Patrick Donnelly of 7th Regiment, Maryland Line; Lieutenant Moses Donley of Bedford County Militia, Pennsylvania; and Captain John McDonnol of Shee's Regiment, Pennsylvania.
No Irish Need Apply? Not anymore