Some witnesses reported that Saint John appeared to be preaching and that he held open a large book in his left hand.

The witnesses reported that the ground around the figures remained completely dry during the apparition although the wind was blowing from the south.

The deliberations of the commission, referred only to the occurrence on 21 August 1879, which omitted "subsequent phenomena", and as a result, there exists no official record for events that occurred after that date.

As most of the documents from the early years at Knock were assumed to have been lost, a second Commission of inquiry, in 1936, was forced to rely upon interviews with the last of the surviving witnesses (who confirmed the evidence they gave to the first Commission), their children, press reports and devotional works printed in the 1880s, which portrayed the original reports in a positive light.

Reports of "strange occurrences in a small Irish village" were featured almost immediately in the international media, notably The Times (of London).

Canon Ulick Bourke joined Timothy Daniel Sullivan and Margaret Anna Cusack in developing Knock as a national Marian pilgrimage site.

Knock pilgrimages combined traditional Irish practices like rounds of the church and all-night vigils with devotions like the Stations of the Cross, benediction, processions, and the recitation of litanies.

This linguistic crisis may be connected with the silence of the Knock visions, as the oldest witness, Bridget Trench, had no English, while the youngest, six-year-old John Curry, was being educated with no Irish.

The suggestion is that the sun served as the light source, which reflected off the school's windows (presumed to have been there) and produced a "natural version of a magic-lantern effect".

Nickell explains that "odd shapes [from diffuse reflections] could produce the requisite pareidolia ... effects in susceptible individuals, especially those who were motivated to see something "miraculous" and were familiar with similar holy pictures.

"[10] Investigator Melvin Harris suggested that a priest may have used a mirror to reflect a magic lantern projection onto the wall from the upper window of the chapel rather than from outside.

[12] Each Irish diocese makes an annual pilgrimage to the Marian Shrine and the nine-day Knock novena attracts pilgrims every August.

Horan presided over a major rebuilding of the site, with the provision of a new large Knock Basilica (the second in Ireland) alongside the old church.

Horan secured from the Taoiseach (prime minister), Charles Haughey, millions of pounds of state aid to build an airport 19 kilometres away, near Charlestown.

On 13 May 2017, Cardinal Archbishop Timothy M. Dolan celebrated a requiem mass when John Curry, the youngest witness to the Knock apparition, was reinterred in St. Patrick's Old Cathedral cemetery in Lower Manhattan after being disinterred from an unmarked grave on Long Island.