In the opening ceremony, a company of the Irish Volunteers, led by Waddell Cunningham, lined the chapel yard and escorted Father O'Donnell into the building.

As Belfast's Catholic population grew after the famine, St. Mary's was deemed too small and thus architect John O'Neill was contracted to design a church big enough for the burgeoning congregation.

Although he was originally contracted to improve the pre-existing church, John O’Neill’s Romanesque design required the effective rebuilding of the late-18th century chapel.

The completed church, which larely remains in place despite later internal changes, was brought forward to the street line and a smaller sexton’s house from the 18th century was demolished.

[8] A new date stone was placed over the doorway in the form of a Potent cross stating; ‘FIDEM / SERVAVI / 1783 / 1868 / 1941’ [1] In the Marian Year of 1954 a Grotto to Our Lady of Lourdes was established under the auspices of the then Administrator, Fr Bernard MacLaverty - an uncle of the Belfast novelist of the same name.