Bl. Frédéric Ozanam (1813-1853) was born on April 23, 1813 in Milan, Italy. On April 23, 1833 Frederic and six companions founded the Society of St. Vincent de Paul. Also, St. Vincent de Paul was born on April 24, 1581. To commemorate these events the Society in the United States celebrates the last Sunday of April as Ozanam Sunday.
Frédéric studied in Paris as a young man, and when certain professors mocked Catholic teachings in their lectures, he defended the Church. He organized a club where Catholics, atheists, and agnostics debated the issues of the day. During one discussion, a club member challenged him: “Let us be frank, Mr. Ozanam; let us also be very particular. What do you do besides talk to prove the faith you claim is in you?”
He was stung by the question and decided that his words needed a grounding in action. In early 1833 he met Sister Rosalie Rendu, a Daughter of Charity, and through their association with her, Frédéric and his companions learned first hand the needs of persons oppressed by poverty. They began visiting Paris tenements and offering assistance as best they could, and ultimately founded a group dedicated to helping individuals in need under the patronage of St. Vincent de Paul. (sources: AmericanCatholic.org, www.svdpid.org/pages/fredericozanam.php)