It was in the fall of 1864 that Father O’Reilly first heard of Gen. William Tecuмseh Sherman’s plan to destroy the entire city of Atlanta by fire. Father O’Reilly was outraged and Patrick Lynch drove the priest to speak to Gen. Henry Slocuм, a subordinate of Gen. Sherman.
“In this meeting, Father O’Reilly argued that the order to burn homes and churches was beyond the normal confines of warfare,” Mears said. “Father O’Reilly pleaded for a compromise that would spare Atlanta’s five churches.”
At first Gen. Sherman rejected the priest’s proposal. But Father O’Reilly would not relent and reminded the general that many of his own troops were Catholics and would create a mutiny if Catholic churches were burned.
As a result of Father O’Reilly’s heroics, five churches in Atlanta—St. Philip Episcopal Church, Central Presbyterian Church, Trinity Methodist Church and Second Baptist Church, as well as the Catholic Shrine of the Immaculate Conception, were spared. In addition, Atlanta City Hall, the Fulton County Courthouse and a residential area between Mitchell and Peters streets were saved.
https://georgiabulletin.org/news/2007/03/city-honors-civil-war-priest-saved-downtown-churches/