Peggy was born 26 July 1900 in Bullaun (also spelled Bulcaun or Bulkane), a townland in Kilbeagh DED in east County Mayo. Her father Patrick Cassidy was a farmer, her mother Bridget Kilgallon. The couple had married 13 March 1875 at St. James' Church in Charlestown, and by 1911 they had raised eleven children.
The 1911 census found Patrick, then 70, and Bridget, 55, living with six of their children in Bullaun — a household of nine, including a servant, Katie Garahan. Peggy, age 12, was listed as a scholar. Her grandfather, Patrick Cassidy Sr., had died 22 May 1873, age 65, of disease of the liver, in the Kilkelly area of the Swinford district.
Bullaun lay in the heart of east Mayo's farming country, within sight of Charlestown and the Dillon estate lands. It was a world of small farmers, National Teachers, and close-knit parish networks — a community that would soon face the upheaval of the War of Independence.
Three of Peggy's brothers served in the Irish Republican Army during the War of Independence, fighting in the East Mayo Brigade under the 2nd Western Division. This was a deeply republican family.
Their mother's relative, M. Kilgallon of Cuilmore, also served, participating in the Sonnagh/Finneran's Mill engagement on 28 June 1921 — a half-hour firefight with an RIC patrol. Cuilmore was the same townland where the Gaffney family also held land, a reminder of how closely the Cassidy and Gaffney families' worlds intersected.
Peggy's siblings had already begun the journey across the Atlantic. The pattern was classic chain migration: one sibling established, then brought the others.
Peggy watched her siblings leave, one by one, for a new world. By the early 1920s, the Cassidy family had a foothold in Ohio. When the time came for Peggy herself to emigrate, the path was already worn.
Like her future husband Philip, Peggy did not sail directly from Ireland to America. Instead, she traveled first to England — a common pattern for Irish emigrants in the 1920s, who often worked in English industrial cities before making the Atlantic crossing.
On 25 May 1925, Peggy boarded the SS Cedric (White Star Line) at Cobh (Queenstown), bound for New York. The ship's manifest listed her as "Margaret Cassidy," age 25, birthplace "British," origin country "Great Britain" — because she had traveled from England.
This British designation proved a puzzle for modern genealogists. She was not findable on Ellis Island passenger searches under "Ireland" because the shipping companies and immigration officials indexed her as arriving from Great Britain, not Ireland. It took detective work with FindMyPast's UK outbound records to locate her on the manifest.
Remarkably, Philip had sailed just ten weeks earlier on the SS Celtic (also White Star Line), arriving 10 March 1925. The timing and shipping line suggest the couple almost certainly coordinated their emigration — Peggy may have followed Philip from England to New York.
After arriving in New York, Peggy made her way to Cincinnati to join her siblings. There, she met Philip Francis Cassidy — a fellow emigrant from the Charlestown/Carracastle area, though from a different branch of the Cassidy family. Philip's father, John Cassidy, had been a National Teacher; his mother, Annie Doherty, was also a teacher. Philip himself had worked as a despatch clerk for the Gaumont Film Hire Service in Birmingham before emigrating.
They married on 5 June 1929 in Cincinnati, Ohio. Their daughter Mary Theresa was born 21 May 1930 in Toledo, Ohio, where Philip had found work as a foundry worker. Philip became a naturalized U.S. citizen on 18 March 1935 in Toledo.
Peggy's life in America unfolded within the tightly knit Irish-American community of Ohio. Her siblings were nearby — Martin, Peter, and Catherine with her Brophy family — creating a diaspora branch of the Cassidy clan in the American heartland.
Philip died in 1943, leaving Peggy a widow at 43. She lived another 19 years, dying in 1962. Her daughter Mary Theresa grew up in Toledo, carrying forward the family name and the memory of her ancestors in County Mayo.