The Clan/Sept History

There are a multitude of ancient meanings and variations associated with the
Irish surnames that are now common throughout the modern world. The original
Gaelic form of the name O Heffernan is O hIfearnain.

Within archives, many different spelling variations exist for the surname O
Heffernan. Ancient scribes and church officials recorded names as they were
pronounced, often resulting in the name of the single person being recorded
under several different spellings. Different spellings that were found include
Heffernan, Heffernam, O'Heffernan, O'Heffron, Hefferen, Hefferney, Heffernon,
Hefferon and many more.
First found in county of Clare, where they held a family seat from ancient
times.
North America accepted thousands of Irish immigrants during the 19th century as
their homeland suffered under foreign imperialistic rule. Although settlers from
the early portion of the century came to North America by choice in search of
land, by far the largest influx of Irish immigrants came to North America during
the Great Potato Famine of the late 1840s. Many of these Irish Families left the
country destitute and in some cases suffering from disease. However, those who
survived the long ocean voyage were especially vital to the development of
industry in the United States and what would become known as Canada. Research of
immigration and passenger lists has shown many early immigrants bearing the name
O Heffernan: Patrick Hefferen settled in Alexandria Virginia in 1817; Bridget
Hefferin settled in Pennsylvania in 1773; Edmund, Edward, John, Michael, Thomas
and William Heffernan arrived in Philadelphia between 1840 and 1860.