Calasanz was born in the Dominican Republic, the sixth of eleven children. His parents owned a farm and had high expectations that their son would one day run the family business. In addition to working long hours on the farm, Calasanz did very well in school and took on the responsibility of protecting those around him who were the targets of gangs and bullies. Because he came to the rescue of those who were victimized, many of the townspeople loved and respected him.
