Bulk of collection is correspondence from Fred Cronin, members of his family, Terence MacSwiney, Muriel MacSwiney, Peter MacSwiney, Sean MacSwiney, Annie MacSwiney, Mary MacSwiney, Art O'Brien, Cardinal Merry Del Val, and others. Included in this collection are documents relating to the family business (Richard Cronin & Sons, undertakers), Terence MacSwiney's burial and the administration of his will. Fred Cronin was a close friend of Terence MacSwiney and was the executor of MacSwiney's will. During the War of Independence Cronin was transport officer to the Cork. No. 1 Brigade of the IRA for a time around 1920 before he was interned by the British authorities at Cork Male Prison and Spike Island between May and December 1921. While he was incarcerated on Spike Island, he joined the other prisoners in a hunger strike which lasted only four days, ending Friday 2nd September 1921. He applied for parole due to the illness of his youngest daughter. His parole application bound him during the period of his release not to "render any assistance, direct or indirect, to persons disaffected towards His Majesty the King, or do any act calculated to be prejudical to the restoration or maintenance of order in Ireland." Republicans generally disapproved of parole-giving and it was permitted only in cases of severe family stress. Cronin had 5 children, of whom the youngest, Maire, required a major operation and was dangerously ill for a time. His wife Katie had died and her sister Mary Roche was looking after the children. During the Civil War Cronin's anti-treaty sympathies saw him interned during the Civil War by the Free State Government in Cork Prison and then Hare Park Camp (Curragh), Co. Kildare from 1922 to 1923.