Margaret Brennan or Brannan 1830

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The following information has been passed down by one of Margaret's grandchildren who has long since passed away but thankfully, he wrote down what she told him.

Margaret Brennan (or Brannan) was born in Glencolumbkille on May 11, 1830. Her parents were Michael Brennan and Ellen Gilespie.  Ellen Gilespie died when Margaret was quite young. When she was a child, Margaret fell from a haystack. As a result, she was crosseyed and possibly blind in one eye.  

Margaret Brennan

Margaret told her grandson that because her family lived by the sea in Ireland, they had plenty of eat, unlike many of the Irish during the Famine.

Michael fought in the Battle of Waterloo and lost a leg so he apparently received a pension. Ellen died quite young. So Michael sent Margaret and one of her brothers to Glasgow to study. The name of the school may have been "National School". There, Margaret learned to be a tailor. She and her brother had one passage to America between them so in 1850, Margaret arrived in New York where she was hired as a tailor for two wealthy families. We do not know how or when but she went to Galena, Illinois, which had a huge Irish population because of the lead mines there.

One July 12, 1855, Margaret and Dennis O'Flaherty were married at the Trappist Monastery of New Mellerary near Dubuque, Iowa, across the Mississippi River from Galena.  The monks of New Mellary came from the monastery in Mount Mellary near Waterford, Ireland.  Dennis was from Inver, Killymard Parish in County Donegal. So both came from County Donegal.

Additional Information
Date of Birth 11th May 1830  
Father (First Name/s and Surname) Michael Brennan  
Mother (First Name/s and Maiden) Ellen Gilespie.  
Spouse (First Name/s and Maiden/Surname) Dennis O'Flaherty  
Place & Date of Marriage One July 12, 1855, at the Trappist Monastery of New Mellerary near Dubuque, Iowa, across the Mississippi River from Galena  


  • Very interesting woman. I've been studying Irish immigration in the lead mining region of Illinois/Wisconsin and would love to learn more about if you have more to share.


    Hope this input doesn't confuse anything, but I found a few interesting sources that reference her. If accurate, Margaret had at least one little sister and at least two brothers, who emigrated to Australia. Possibly more...


    The 1860 census, Galena, IL, enumerates in the house of Dennis and Margaret Branan a girl named Rose Branan, 16 years old, born in Ireland, listed as sister-in-law. So perhaps Margaret had a little sister come live with her? See:


    In "The Illustrated History of Nebraska" Vol. III (1913), it profiles Dennis James Flaherty, son of Dennis and Margaret. It says: "FLAHERTY, DENIS JAMES, attorney at law, Lincoln, Neb., was born at Galena, Ill., February, 1875, son of Denis O. Flaherty, who was born in County Donegal, Ireland, February 12, 1834, and came to America in 1855. In 1856 he was married to Margaret Brennan, at Benton, Wis., who was also a native of County Donegal, Ireland, born in 1836. Mrs. Flaherty was the daughter of William Brennan, who served under Wellington in the wars against Napoleon I. Two of her brothers, Michael and James, have held office for many years under the British government of Australia, where they located in 1850. Her death occurred October 9, 1909. Denis O. Flaherty engaged in the milling business at Galena, Ill., until 1865, when he went to Idaho, and took up a placer claim near Boise, which he worked for two years, then returned to Illinois and engaged in farming near Galena until 1877, when he moved to Cedar county, Ned., and engaged in farming and stock-raising. He served as county commissioner of Cedar county three terms. His death occurred February 12, 1896." The article goes on another paragraph or so listing their children with respective biographical information. See:  

    On 27 July 1856, a man named Michael Flaherty married Catherine Brenan in Jo Daviess County, IL. Galena, where Margaret is living at this time, is the capital of Jo Daviess County. It seems likely that Catherine is a relation of Margaret.




    Sunday 3rd June 2018, 10:40AM
  • Hello,

    Yes, Margaret (one of my great-great grandmothers) did have at least one brother who emigrated to Australia that I know of.  There may well have been more siblings who also went.  The article about her son that you showed above is not entirely accurate. We know that the O'Flahertys married at the Trappist Monastery at Peosta (south of Dubuque), Iowa.  But Benton is nearby and Michael O'Flahertys lived there.   I believe the Michael Flaherty you named is a brother to Dennis O'Flaherty (husband of Margaret) based on our information. It makes sense that Catherine Brenan you noted above is her relative.

    I don't know if you have been there but I visit Galena fairly often and was just there in March visiting the archives at their wonderful library.

    If you would like to connect offline so we can discuss Margaret further, feel free to email me at Thanks much!


    Sunday 3rd June 2018, 11:34AM

    According to LDS website (Free), Dennis & Margaret applied for their marriage license on June 28, 1955.  (you can write for a copy)

    You can see them on the original 1860 and 1870 censuses also free online at the LDS site (Church of the Later Day Saints).  

    Name:                                  Dennis O. Flagherty

    Event Type:                        Marriage

    Event Date:                         28 Jun 1855

    Event Place:                        Dubuque, Dubuque, Iowa, United States

    Gender:                               Male

    Spouse's Name:                 Margaret Brinnen

    Spouse's Gender:            Female

    Reference ID:                    bkl p 284 cn 851

    GS Film Number:              001035386

    Digital Folder Number:  004311184

    Image Number:                 00267

    Citing this Record:

    "Iowa, County Marriages, 1838-1934," database, FamilySearch ( : 4 November 2017), Dennis O. Flagherty and Margaret Brinnen, 28 Jun 1855, Dubuque, Dubuque, Iowa, United States; citing reference bkl p 284 cn 851, county courthouses, Iowa; FHL microfilm 1,035,386.



    Name:  Dennis Faherty

    Event Type:        Census

    Event Date:         1860

    Event Place:        Galena 5th Ward, Jo Daviess, Illinois, United States

    Gender:               Male

    Age:       27

    Race:     White

    Birth Year (Estimated):  1833

    Birthplace:          Ireland

    Page:     166

    Household ID:    1228

    Affiliate Name:  The U.S. National Archives and Records Administration (NARA)

    Affiliate Publication Number:      M653

    Affiliate Film Number:   189

    GS Film Number:              803189

    Digital Folder Number:  005165760

    Image Number: 00170


    Household          Role       Sex         Age        Birthplace

    Dennis Faherty                  M            27           Ireland

    Margaret Faherty             F              27           Ireland

    Edward M Faherty           M            3              Ills.

    Cornelius J Faherty          M            2              Ills.

    Rose Branan                       F              16           Ireland  (probably Brennan/Brannan

    Danl Griffin                         M            23           Ireland


    Citing this Record:

    "United States Census, 1860", database with images, FamilySearch ( : 13 December 2017), Dennis Faherty, 1860.


    Name:  Edward O Flagherty

    Event Type:        Census

    Event Year:         1870

    Event Place:        Illinois, United States

    Gender:               Male

    Age:       13

    Race:     White

    Race:     W

    Birth Year (Estimated):  1856-1857

    Birthplace:          Illinois

    Page Number:   10

    Household ID:    73

    Line Number:    25

    Affiliate Name:  The U.S. National Archives and Records Administration (NARA)

    Affiliate Publication Number:      M593

    GS Film number:              000545733

    Digital Folder Number:  004263010

    Image Number: 00690


    Household          Role       Sex         Age        Birthplace

    Denis O Flagherty                            M            37           Ireland

    Margaret O Flagherty                     F              39           Ireland

    Edward O Flagherty                        M            13           Illinois

    John O Flagherty                              M            11           Illinois

    Margaret O Flagherty                     F              9              Illinois

    Ellen O Flagherty                              F              7              Illinois

    Mary O Flagherty                             F              3              Illinois

    Denis O Flagherty                            M            1              Illinois


    Citing this Record:

    "United States Census, 1870," database with images, FamilySearch ( : 12 April 2016), Edward O Flagherty in household of Denis O Flagherty, Illinois, United States; citing p. 10, family 73, NARA microfilm publication M593 (Washington D.C.: National Archives and Records Administration, n.d.); FHL microfilm 545,733.



    Monday 22nd October 2018, 09:39PM