This book was researched by Leland Dudley O'Brien for several decades. The family origins in Louisiana began in 1800 with the arrival of two brothers from Ireland. This record begin the record of the O'Brien clan in LA and continues their ancestery back to the Name sake Brian Boru, King of Ireland. There are several Libraries in Louisiana that maintain copies, LSU-Eunice, The final document was assembled by my Mother, Thoma (not a misspelling) Adams O'Brien. It is my intention, as I was looking at software today, to update this document to include the additional information of this line, to include my wife and children and grandchildren. It will take a while.