This collection contains correspondence addressed to Reverend John O’Brien. Most of the letters are thank you notes from across the country for souvenir editions of The Sacred Heart Review issued after the Eucharistic Congress in Montreal in 1910. The collection also contains letters that were collected by O’Brien, including one signed by Irish politician Daniel O’Connell. Additionally, there is a facsimile of a Protestant oath and three images relating to the family of Ansel and Violet O'Connor.