The Clan/Sept History

The original Gaelic versions of today's Irish names demonstrate a proud, ancient
past. The original Gaelic form of the name MacTiernan is Mac Tighearnain, which
is derived from the word tighearna, which means lord.

Pronunciation, rather than spelling, guided scribes and church officials when
recording names during the Middle Ages. This practice often resulted in one
person's name being recorded under several different spellings. Numerous
spelling variations of the surname MacTiernan are preserved in these old
documents. The various spellings of the name that were found include Tiernan,
Tierman, Ternan, Kiernan and others.
First found in county Cavan, at Tullyhunco where the "Annals of the Four Master"
show 33 Tiernans almost all as Chiefs of Teallach Donnchadha.
Thousands of Irish Families left for North American shores in the 19th century.
These people were searching for a life unencumbered with poverty, hunger, and
racial discrimination. Many arrived to eventually find such conditions, but many
others simply did not arrive: victims of the diseased, overcrowded ships in
which they traveled to the New World. Those who lived to see North American
shores were instrumental in the development of the growing nations of Canada and
the United States. A thorough examination of passenger and immigration lists has
disclosed evidence of many early immigrants of the name MacTiernan: John Tierman
settled in Philadelphia in 1802; John Tiernan settled in Philadelphia in 1845;
also 1850; 1867; and 1880; Patrick Tiernan settled in Philadelphia in 1846.