My Duggans were all married and baptized at St. Michael's RC parish in Tipperary Town. John and William emigrated to St. Louis, MO 1849 and 1856. Honora emigrated to New
Orleans 1850, then removed to St. Louis about 1871.
Here's a real coincidence. In 1844 William married (in
Tipp Town) Johanna
O'Dwyer. They had four children born in Tipperary - Catherine 1845, Thomas, 1847, Mary 1850, Patrick 1852. Another child was born in
Massachusetts in 1855, and then two more after they finally arrived in St. Louis. The family is enumerated in the 1860 census in St. Louis.
I have a great deal of information on the Duggans after their arrival in St. Louis. Nowhere in a census, marriage, baptism, death/cemetery record or family memoir is there a George.
There are a number of Duggan-O'Dwyer links contained in baptism records from
Tipp Town. First, of course, is Catherine
O'Dwyer - Patrick Duggan's spouse. They were married in 1803. Then there is Johanna
O'Dwyer who married William in 1844. A witness was Eliza
O'Dwyer. Charles
O'Dwyer was sponsor at 1836 baptism of James
O'Brien, son of Mary
Duggan and William
O'Brien. Mary
O'Dwyer was sponsor at 1845 baptism of Ellen
Fitzgerald, daughter of Honora
Duggan and William
Fitzgerald. Michael
O'Dwyer (could this be your "
Mick"?)was sponsor at 1840 baptism of John
O'Brien, son of Mary
Duggan and William
O'Brien.
Clearly there are close connections between the
O'Dwyer and
Duggan families in Tipperary evidenced by the
O'Dwyer presence at the important family events -- marriages and baptisms. It's so difficult to sort them all out because of the naming tradition, where the same forenames are constantly repeated in the families from one generation to the next. Middle names were not customary at this time so there's no help there.
I've not found any connection to
Harrigan in
Doon. Don't know if this has been helpful to you. Have you researched
Cousin Mick O'Dwyer? Perhaps that might unearth a clue that would be helpful.