The Clan/Sept History

Irish names tend to vary widely in their spelling and overall form. The original
Gaelic form of the name O Cassidy is O Caiside.

Many spelling variations of the surname O Cassidy can be found in the archives.
One reason for these variations is that ancient scribes and church officials
recorded names as they were pronounced, often resulting in a single person being
recorded under several different spellings. The different spellings that were
found include Cassidy, Cassady, Cassiday, Cassedy, Cassedey and others.
First found in Fermanagh, where the Irish sept claims direct descent from the
Irish King Colla da Crioch who was banished from Ireland in 327.
A great mass of Ireland's native population left the island in the 19th century,
seeking relief from various forms of social, religious, and economic
discrimination. This Irish exodus was primarily to North America. If the
migrants survived the long ocean journey, many unfortunately would find more
discrimination in the colonies of British North America and the fledgling United
States of America. These newly arrived Irish were, however, wanted as a cheap
source of labor for the many large agricultural and industrial projects that
were essential to the development of what would become two of the wealthiest
nations in the western world. Early immigration and passenger lists indicate
many people bearing the O Cassidy name: Patrick Cassidy who settled in Rhode
Island, and later moved to Norwich in Connecticut, where he became one of
America's first surgeons. Edward, Hugh, James, John, Patrick, Thomas and William
Cassady who all arrived in Philadelphia between 1840 and 1865.

Motto Translated: Thou may'st break, but shalt not bend me.