The Clan/Sept History

The ancient Gaelic form of the Irish name O Duggan was O Dubhaigan. The first
portion of the name is the word dubh, which means black; the second portion is
likely some obsolete Irish personal name.

In the Middle Ages, the largely illiterate society in Ireland had little control
over how their names were to be recorded. Spelling variations revealed in the
search for the origin of the O Duggan family name include Dugan, Duggan,
O'Duggan, Dougan, Douggan, Dewgan, Deugan and many more.
First found in County Clare, where they held a family seat from very ancient
times. The family line is directly traceable to Fergus Mor(Fergus the Great). In
turn his ancestry is associated with King Ir, brother of the equally famous
Heremon.
Many Irish Families did not fare so well within the English-ruled Ireland.
Besides racial and religious discrimination, many families were renting out
small tracts of farmland from absentee landowners at often unreasonable rates.
Beginning in the late 18th century, moderately well off Irish families decided
to emigrate to British North America or the United States in order to own their
own plot of land. A radical change occurred in the 1840s, however, with the
Great Potato Famine of the 1840s. Up to this point, the island's population had
been increasing rapidly and a steady demand over the years for grain crops had
depleted soil. Two failed crops and one poor one caused widespread disease and
starvation. Thousands boarded ships looking for opportunities elsewhere. North
America welcomed them as a source of cheap labor required for the many
industrial and infrastructure projects underway, and as a means to quickly
occupy the western regions. Research into immigration and passenger ship lists
indicates that people bearing the name O Duggan were among the earliest settlers
to arrive in North America: James Dugan who settled in New York State in 1775;
John Duggen, who arrived in Maryland in 1739; Cornelius Duggin, who arrived in
Albany, NY in 1762; John Duggin, who came to Boston in 1765.