[3] Due to an influx of Irish immigrants to the nearby Hell's Kitchen neighborhood, Sacred Heart Church was unable to accommodate the need and a second parish was established.

[5] Around 1920 the Theater District started to move uptown into this area, and actors, dancers, and musicians became prominent worshipers at the church, replacing the traditional, working class congregants.

[1] Leonard sought the special permission of the Archbishop of New York for Masses to be celebrated there at 4 A.M. (which was banned by canon law at the time) to accommodate the non-standard schedules of theater workers and thus make worship convenient for them.

[2] It gained worldwide attention when the church was the setting for the funeral of Rudolph Valentino, as well as of the wedding of Douglas Fairbanks Jr. to Joan Crawford.

[2] Celebrity worshipers were often in attendance, as well as theater goers, and the nearby location of Madison Square Garden during that time helped to provide a steady stream of visitors.

Many were held virtually under siege in decaying single room occupancy hotels or in tenements with a tub in the kitchen and a shared bathroom in the hallway.