The Clan/Sept History

All Irish surnames have a unique and often romantic meaning. The name Mangan
originally appeared in Gaelic as O Mongain, which is derived from the word
mongach, which means hairy.

Numerous spelling variations of the surname Mangan exist. A partial explanation
for these variants is that ancient scribes and church officials recorded names
as they were pronounced, often resulting in a single person being recorded under
several different spellings. Different spellings that were found include Mangan,
Mongan, Mongin, Mungan, Mungen, Mongun, O'Mongan, O'Mongin, O'Mungen, O'Mongun,
O'Mongun, O'Mangan and many more.
First found in Connacht, where they were anciently seated and styled as one of
the Irish Clanns who were descendants of King Niall of the Nine Hostages. They
were descended through Eochy Moyvane, to Niall Mor, his son, the great Niall of
the Nine Hostages. Descended was O'Mongain the great chief of the Mangans whose
territories included branches in Mayo, Connacht, Cork and Limerick.
The 19th century saw a great wave of Irish migrating out of their homeland in a
great measure due to the oppressive imperial policies of the English government
and landowners. Many of these Irish Families sailed to North America aboard
overcrowded passenger ships. By far, the largest influx of Irish immigrants to
North America occured with Great Potato Famine during the late 1840s. These
particular immigrants were instrumental in creation of the United States and
Canada as major industrial nations because the many essential elements such as
the roadways, canals, bridges, and railways required an enormous quantity of
cheap labor, which these poor immigrants provided. Later generations of Irish in
these countries also went on to make valuable contributions in such fields as
the arts, commerce, politics, and education. Extensive research into immigration
and passenger lists has revealed many early immigrants bearing the name Mangan:
John, Mary and Judy Mangan who arrived in New York State in 1853; Francis,
Henry, James, John, Michael, Patrick, Thomas, and William Mangan, all arrived in
Philadelphia, Pennsylvania between 1826 and 1868.