1875 United States census records show William O’Mulcahy (age 29, born in Canada around 1846) married to Maggie (age 30, from Ireland). The couple resided in Rochester, Minnesota.
At this time a public-spirited citizen of Rochester, Minnesota, one William O’Mulcahy, proposed the organization of a joint-stock company (The Minnesota Colonization Company) as a means of underwriting the settlement of indigent people on some of the colony lands still not claimed in Swift County. O’Mulcahy reasoned that poor persons who were willing to work hard could quickly repay any backers who were prepared to advance them the initial capital necessary for starting a wheat farm in Swift County. O’Mulcahy was well known in Irish circles in Minnesota. (Catholic Colonization on the Western Frontier, James P. Shannon, Yale University Press, 1957, Page 108)
The Minnesota Colonization Company, organized in 1877 by William O’Mulcahy, a prominent Irishman from Rochester, failed for lack of financial backing, for the American Irish consistently refused to invest in colonization ventures, preferring to send money to family members in Ireland or to donate to groups working for Irish political and economic reform. (Irish in Minnesota, Ann Regan, Minnesota Historical Society, St. Paul, 2002, Page 22)
Catholic Union Organized. A meeting of the various Catholic benevolent societies in the State was held yesterday morning in the Academia rooms of the cathedral. The organization of a State union was completed by the election of the following officers: William O. Mulcahy, of Rochester, president… (The Saint Paul Daily Globe, Wednesday Morning, September 4, 1878, Volume I, Number 233, Page 4)
Mr. W. O. Mulcahy (of Faribault) was then declared president (of the Catholic Total Abstinence society) for the ensuing year. (The Saint Paul Daily Globe, Friday Morning, June 20, 1879, Volume II, Number 157, Page 2)
William O’Mulcahy was chosen secretary… (of the Hancock and English club of Faribault, Minnesota (The Saint Paul Daily Globe, Thursday Morning, September 16, 1880, Volume III, Number 260, Page 1)
Meeting of the State Supreme Court for the October Term. William O Mulcahy, respondent, vs A M Florer, appellant, November 13. (The Saint Paul Daily Globe, Wednesday Morning, October 6, 1880, Volume III, Number 280, Page 2)
All branches of business are represented at Grafton (Dakota Territory). Dubuque, Iowa, parties, established a bank there a few months since, under the personal management of J. L. Cashel, cashier, and Wm. O’Mulchay, assistant cashier. Soon after opening out their building was destroyed by fire, but nothing daunted work was immediately commenced on a new building, in which business was resumed Saturday last. (The Saint Paul Daily Globe, Tuesday Morning, March 28, 1882, Volume V, Number 87, Page 2)
1885 Dakota Territory census records show W. O. Mulcahy (age 36, cashier Grand Forks National Bank, born in Ontario) married to Margaret (age 36, born in Ireland). Children were Bridget (age 8, born in Minnesota), Willie (age 5, born in Minnesota), Patricia (age 4, born in Minnesota), Mary (age 3, born in Dakota Territory), and Patrick (age 7 months, born in Dakota Territory).
Wm. O’Mulcahy, cashier Grand Forks National Bank, residence 520 North Seventh in Grand Forks. Michael L. McCormack was president of the bank and F. T. Walker was vice-president. (Grand Forks and North Dakota Manual for 1885, William L. Dudley, Plaindealer Book and Job Rooms, Grand Forks, 1885, Page 97)
After the Grand Forks/East Grand Forks tornado of June 16, 1887, William O’Mulcahy was appointed the head of the tornado relief committee.
Mrs. W. Mulcahy has returned from Faribault and St. Paul. (The Saint Paul Daily Globe, Saturday Morning, May 19, 1888, Volume X, Number 140, Page 11)
GRAND FORKS, Dak., July 24. – The greatest boom Grand Forks has sustained for many a day has been occasioned by a determination of a syndicate to erect a mammoth $100,000 hotel (Dacotah). The syndicate is composed of representative men of the Northwest. The directors are: F. T. Walker, J. S. Bartholomew, William O. Mulcahy, George A. Eastman and George B. Clifford. (The Saint Paul Daily Globe, Wednesday Morning, July 25, 1888, Volume X, Number 207, Page 8).
William O’Mulcahy, a prominent attorney of Grand Forks, is in the city. (The Saint Paul Daily Globe, Wednesday Morning, August 22, 1888, Volume X, Number 235, Page 2)
Grand Forks & Dakota Southern Railroad Company – From a point near Grand Forks, south to a point near Fargo, also west to a point on the Missouri river near Washburn, Dak.; length, 275 miles; capital, $3,000,000; shares, $100 each; directors, M. L. McCormack, Grand Forks, Dak.; George B. Clifford, Grand Forks, Dak.; William O’Mulcahy, Grand Forks, Dak.; George A. Eastman, Grand Forks, Dak.; F. T. Walker, Dubuque, Io.; J. C. Moore, Manchester, N. H.; Sumner Wallace, Rochester, N. H. (The Saint Paul Daily Globe, Saturday Morning, January 5, 1889, Volume XI, Number 5, Page 10)
A WHOLESALE LIAR. Dakotians Who Know Le Caron Cast Reflections on His Veracity. GRAND FORKS, Dak., Feb. 8. – Cashier Mulcahy, of the Grand Forks National bank, and Deputy Sheriff O’Connor are well acquainted with Dr. Le Caron who is creating such a sensation in London as a Times witness in the Parnell case. Mulcahy affirms that in 1881 he was present in the Palmer house, Chicago,… (The Saint Paul Daily Globe, Saturday Morning, February 9, 1889, Volume XI, Number 40, Page 1)
The Grand Forks City Directory for 1889-90 shows William O’Mulcahy as vice-president of the Grand Forks Loan and Land Company. He is still the cashier at the Grand Forks National Bank.
Chairman of a Special Seed Wheat Committee (Journal of the Senate of the First Legislative Assembly, Tribune Printers and Binders, Bismarck, Dakota Territory, Wednesday, March 12, 1890, Page 840)
William O. Mulcahy and George A. Batchelder, of Grand Forks, are registered at the Merchants’. (The Saint Paul Daily Globe, Sunday Morning, June 8, 1890, Volume XII, Number 159, Page 8).
Wm. O’Mulcahy is the guest of the city. Mr. O’Mulcahy came up from St. Paul to enjoy the festivities of the grand opening (of the Grand Forks Opera House). (Grand Forks Daily Herald, Wednesday Evening, November 12, 1890, Volume XX, Number 10, Page 1)
Accompanying the notice was a petition which alleges that the title to a large tract of mineral land in St. Louis county was obtained from the state auditor by fraud, deceit and the collusion of Adolph Bierman, Robert Jamison, Tams Bixby, Henry W. Childs, Andrew Irwin, William O’Mulcahy, William H. Angell and Robert C. Elliot, who were among the state officials… (The Saint Paul Daily Globe, Tuesday Morning, September 29, 1891, Volume XIII, Number 272, Page 2)
1895 census records show William O’Mulcahy (age 48, born in Canada) married to Margaret (age 47, born in Ireland). The couple was now living in St. Paul, Minnesota. Children were Bridget (age 18, born in Minnesota), William (age 16, born in Minnesota), Patricia (age 14, born in Minnesota), Mary (age 12, born in North Dakota), and Patrick (age 10, born in North Dakota).
1920 United States census records show William O’Mulcahy (age 72, born in Canada) married to Margaret (age 71, born in Ireland). Patrick J. (age 34) was still living with the couple and they now resided in Seattle, Washington.
William O’Mulcahy died February 18, 1921 (age 73) in Seattle, Washington. Spouse Margaret was still alive at the time.
O’Mulcahy – On February 18, 1921, William O’Mulcahy, aged 73 years, beloved husband of Margaret O’Mulcahy and father of Mrs. Birdie Lyon, W. E. and P. J. O’Mulcahy and Mrs. J. W. Donnelly. Requiem mass, Monday, 9 a. m., St. James Cathedral. Interment Calvary. Remains at residence, 1533 12th Ave. S. Joseph R. Manning, funeral director, 11th and Olive. (Seattle Times, Sunday, February 20, 1921, Page 17)