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McMahon Genealogy and McMahon Family History Information

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  • James McMahon (c.1757 - c.1830)
  • James McMahon (1788 - 1814)
    From Genealogy of Margaret Meyer Simpson, Person Page - 55 James McMahon [1] M, b. 12 July 1788, d. 26 December 1814 James was born on 12 July 1788 at Jonesboro, Washington County, Tenn...
  • Janette McMahon (b. - c.1820)
  • John Blair McMahon (1755 - 1814)
    From Genealogy of Margaret Meyer Simpson, Person Page - 55 John Blair (Brooks?) McMahon [1] M, b. 6 June 1755, d. 26 March 1814 John was born on 6 June 1755 at Frederick County, Virgini...
  • Margaret McMahon (b. - 1811)

About the McMahon surname

McMahon or MacMahon (old Irish: MacMathghamha modern Irish: MacMathúna) is an Irish surname. History; Two septs arose in Ireland with the surname McMahon, one in the Kingdom of Oriel in the province of Ulster, around modern County Monaghan; the second in Thomond, in the province of Munster, in modern County Clare. The sept in County Clare descends from Mathgamain mac Cennétig, brother of the High King of Ireland and founder of the O'Brien dynasty, Brian Boru. The McMahons rose to power in 1250 AD, in the Kingdom of Oriel, which roughly evolved into the present day County Monaghan. They were chieftains of the territory for nearly 400 years.