[2] After finishing high school, Dunn traveled to Ellicott City, Maryland to enroll at St. Charles College; he graduated there in 1890.

[5] In the early 1900's, the City of New York started an investigation of Catholic Charities in the archdiocese that quickly devolved into a bitter dispute between them.

Dunn later testified before the Thompson Legislative Committee, tasked with the New York State Legislature with investigating the issue.

[9] In addition to his duties as director of the Society for the Propagation of the Faith, Dunn was named pastor of the Church of the Annunciation in Manhattan.

[9] Dunn served as ecclesiastical superior of the Sisters of St. Dominic motherhouse in Newburgh, playing a role in their establishment of Greater Mount Saint Mary, a Catholic high school in that town.