John's parents were John O'Brien and Mary Gallagher. Some sources have spelled his father's surname as O'Bryan and his mother's maiden name as Gallacher or Gallagher.

Family records indicate his parents were both born in Ireland and married about 1830.

It is believed they immigrated about 1832, shortly after the birth of their first known child, Michael.

They then migrated to Philadelphia, Pennsylvania. His mother's christening record and death record have recently been found.

Their children were Michael 1831-1869; James 1833-1886; Mary 1835-unk; George 1837-1862.; Frank 1840-1863; and the only fully documented is John, (the younger) to whom this memorial is dedicated.

John, son of John and Mary Gallagher O'Brien was born 16 May 1839 at Philadelphia, Pennsylvania. He was the last child and all others were also born at Philadelphia, except for Michael, whose death record indicates his birth in Ireland. It is the fact that John, himself, gave a birth place of Philadelphia when he attended to religious ceremonies of his faith, that convinces one that Baltimore Maryland may have been a temporary, previous location of the family before any American births occurred.

His four brothers died in the prime of their lives and little is known of his sister, Mary.

It is concluded that John migrated west alone, perhaps as a teamster with a wagon train, as he first appears in the Salt Lake Valley at his marriage to Rebecca Angelina King, 12 November 1863 in Layton, Davis, Utah.

Children - John Olin O'Brien, Thomas Jefferson O'Brien, James Alma O'Brien, George Elias O'Brien, Rebecca Angelina O'Brien, Jesse Moroni O'Brien, Jonathan Silas O'Brien, Mary Jane O'Brien, William LeRoy O'Brien, Clarence Alphonso O'Brien, Robert Elmer O'Brien, Uriel Winfred O'Brien.

Utah Death Certificate

Davis Clipper, 1904-03-04:

JOHN O'BRIEN DEAD
"John O'Brien of Layton died at the home of his daughter, Mrs. W.B. Nalder, Monday evening, after an illness of more than a year. For quite a long time the doctors treated him for abscess of the lungs and he appeared to be getting better but it finally terminated in consumption.
Deceased was born in Baltimore, Md., [reported by a son; however, John recorded he had been born in Philadelphia, PA.] and had he lived till next May he would have been sixty-five years old.
He came to Utah in 1857. He lived in South Weber a while but his home has been in Layton nearly all the time since his arrival here.
In 1863 he married Rebecca A. King, sister of T.F. King of Farmington. Twelve children were born to them; ten boys and two girls; eight of them surviving him.
Deceased made no religious pretensions but was an honorable and straight forward gentleman.
Nearly all his children have a pretty good education."