On January 9, 1835, Pallotti founded the Union of Catholic Apostolate. He expressed his idea in the following words: “The Catholic Apostolate, that is the universal apostolate, which is common to all classes of people, consists in doing all that one must and can do for the greater glory of God and for one’s own salvation and that of one’s neighbour”. He further states, “Whether young or old, healthy or sick, alone or in community, in any position of life given to them by God, all can participate fully in the apostolic mission of Jesus Christ by any means whatever”. On July 11, 1835 Pope Gregory XVI gave his approval.

The Society was placed under the protection of Mary, Queen of the Apostles. During the cholera plague in 1837, Pallotti constantly endangered his life while ministering to the cholera stricken. In 1838, the Society Pallotti founded was ordered to be dissolved on the perception of a duplication of the Society for the Propagation of the Faith. Pallotti appealed to the Pope against the decree and the order of dissolution was withdrawn.

On October 28, 2003, the Union of Catholic Apostolate was declared an International Public Association of the Faithful by the Decree of the Pontifical Council of the Laity. Thus, “The Union of the Catholic Apostolate, a gift of the Holy Spirit, is a communion of the faithful who, united with God and with one another in accordance with the charism of St. Vincent Pallotti, promote the co-responsibility of all the baptized to revive faith and rekindle charity in the church and in the world, and bring all to unity in Christ”