Mathias Breen was born in 1832, probably at Lakyle South in Killofin parish in Co. Clare, on the Kilkerin peninsula a few miles from the town of Labasheeda.
His father was Thomas Breen (who appears in the Griffith's Valuation book as "Thomas Brien," undoubtedly a misspelling). Thomas Breen was probably born at Balina in Killofin parish around 1810, the son of an elder Mathias Breen and his wife Ann McGrath Breen (she being buried in the nearby Killofin graveyard with a headstone dedicated by her husband).
The McGrath family had been at Balina since the 18th C. and descendants still farm land there. The elder Mathias MAY have been from Kilmihil parish around Kiltumper originally. The elder Mathias, Thomas and a James (sibling to Thomas?) are found at Balina in the 1826 "Registry of Persons Licensed to Keep Firearms." The Firearms Registry of 1832 shows that the Breen's registration was endorsed by Col. Crofton M. Vandeluer, "local magistrate." The Griffith's Valuation of the Thomas Breen land (the 1855 Griffiths has him as "Thomas Brien") at S. Lakyle in Kilofin Parish shows that Col. C.M. Vandeluer was their landlord. The Vandeluer Estate had its seat at Kilrush, a few miles west of the Kilofin peninsula on the N. Bank of the Shannon.
Thomas, son of Mathias the elder and father of Mathias, married a Mary Morony, who was probably from Kiltumper in Kilmihil. She died in 1846 after giving birth to (at least) Mathias, Margaret, Thomas, Michael and Denis. Mathias and Margaret (chirdren) emigrated in 1851 through Liverpool, arriving in New York in August 1851 on the Sailing Ship Sandusky. Their brothers' Thomas and Michael arrived later and Denis stayed in Clare with his father, Thomas, and is found (in Petty Sessions Court Proceedings) living with his father at Lakyle South in the 1860's-'70's. Thomas died in the 1880s and Denis is later found living on land at Kiltumper (near the Holy Well) that had previously been in the possession of a Michael Morony (who we therefore assume may have been his grandfather). Denis Breen subsequently sired a long line of descendants in Kilmihil Parish, one of whom was the a local martyr to the Uprising, John Breen, who was shot on the streets of Kilmihil and to whom there is a local monument. Descendants of Denis Breen are living in Kilmihil town today.
In the US, Mathias started a career in stonecutting around Washington, D.C. and Richmond, VA. He was "caught" in Richmond by the Civil War and pressed into service for a few years as a Confederate hospital guard. Near the end of the war he made it across the lines to Washington with his wife, Ann Howard Breen (from Co. Galway, probably the Athenry area) and son Thomas. In Washington he workd as a stone cutter and mason. In about 1868 he successfully bid on a contract to build a US Post Office and Customs House in St. Paul, MN and relocated there with his wife, son and daughter Mary Louise (later Quinlan). In St. Paul Mathias had a long and successful career as a builder in stone. He died in 1890 and is buried in Calvary Cemetery in St. Paul.
The principle source of information on Mathias Breen is his biography in "History of St. Paul", by C.C. Andrews, found in the library of the Minnesota Historical Society in St. Paul. Additional facts have been sourced from Griffith's Valuation of 1855, the 1832 Registry of Persons Licensed to Keep Firearms, the US compendium of missing person ads from the Boston Pilot called "Searching For Missing Friends," Ship arrival records from New York in 1851 and various US Census and military records.