He subsequently returned to Russia to cover the 1918-1922 Siberian Intervention to assist the anti-communist White Army of Admiral Alexander Kolchak during the Russian Civil War.
Edmund A. Walsh, McCullagh's detailed reports about the 1923 Moscow show trial prosecution by Nikolai Krylenko of Archbishop Jan Cieplak, Exarch Leonid Feodorov, Monsignor Konstanty Budkiewicz, and other Catholic clergy and laity reached a worldwide audience, much to the shock of the Soviet State.
[7] McCullagh's detailed account of his visit and of the Cieplak show trial were published in the 1924 volume The Bolshevik Persecution of Christianity, which was immediately translated into French, German and Spanish.
On 10 April 1923, People's Commissar for Foreign Affairs Georgy Chicherin wrote a letter to fellow Politburo member Joseph Stalin, which described the political fallout from Fr.
Walsh and Captain McCullagh's successful efforts to globally publicize both the Cieplak show trial and the execution of Monsignor Konstanty Budkiewicz on Easter Sunday, 1923.
Due to both the trial and Monsignor Budkiewicz's subsequent execution, the meeting had been cancelled and the senator had been forced to indefinitely postpone the founding of a committee to press for diplomatic negotiations.
"[9] In 1927, Father Wilfrid Parsons arranged payment from the Knights of Columbus to "smuggle" McCullagh into Mexico to cover the Cristero War for an American audience.