Dr Crowley was a Medical Officer in Ballycastle for 33 years and is buried in Doonfeeney cemetery with the remains of his son, Dunbar, who died at the age of three and a half years.
He was born in Cork in 1870, received his earlier education in Cork and then graduated from the Royal University, Edinburgh. At the age of 50, he learned to speak the Irish language and became a fluent speaker. He was also an accomplished public speaker.
He became associated with the Sinn Fein movement almost from its inception and took a prominent part in all the activities of the organisation. In 1918 he was elected Sinn Fein TD for North Mayo, defeating by a decisive majority the then sitting member, the late Alderman D. Boyle MP. He was elected again in 1924 but did not contest the constituency after that. He held the rank of Battalion Commandant in the IRA and played an active part in the Wart of Independence.
During 1920 his residence was raided on many occasions by Crown forces. One night he was taken from his bed and badly beaten. He was put into a lorry to be taken to Ballina but on the journey he jumped from it and escaped after several volleys of shots were fired at him. He then went 'on the run' and was next heard of in his native Cork. Here he was arrested and paraded through the streets of Cork City tied to a gun. He escaped again and after a serious operation, took part in the activities of the IRA in different parts of the country.
In 1922 he was arrested by Free State forces and held in Ballina workhouse, from which he was released by Republican forces on 12th September 1922 when they stormed and captured Ballina. The terrible beatings and hardships he underwent during the Anglo-Irish struggle and the civil war left him in very bad health. However, he fought against the steady inroad of disease with the iron will he possessed.
He was responsible for the sale of Dail Eireann Bonds in North Mayo and from 1918 to 1925 was President of the North Mayo Sinn Fein Executive. His political activities in later years were not so prominent owing to the state of his health, but he never wavered in his convictions in regard to the policy of Sinn Fein. He was a man who resisted all pressure, risked unpopularity and even imprisonment in pursuit of his beliefs.
As a medical man, he was foremost in the ranks of his profession. One of his qualifications was as a specialist in the treatment of the eyes. On the wildest of winter nights, he trudged over the mountains and through the bogs to tend to sick people. He is remembered for his unbounded charity that left him a relatively poor man.
He died at the age of 64 years. Most Rev Dr Naughton, Bishop of Killala, preceded the coffin as it was borne from St Brigid's Church and his funeral was attended by many clergymen. Over 1,000 Old IRA men were present with a special 100 strong detachment that marched behind the coffin, wearing white sashes.
The Minister for Justice, Mr PJ Rutledge was also present, as were many TDs. At the graveside the prayers were said by Archdeacon Munnelly who, in his tribute, said Dr Crowley was a devout Catholic who took a personal interest in the erection of the new Church in Ballycastle.
A monument was erected to the memory of Dr Crowley. It is on the Killala road just outside the town of Ballycastle.