Abbot Gueranger, O.S.B. says in The Liturgical Year that devotion to St. Joseph was reserved for "these latter times." He quotes the 1645 book La gloire de Saint-Joseph by Father Jean Jacquinot, S.J.:
O thou bright sun, thou father of our days! speed thy onward course, and give us that happy day whereon are to be fulfilled the prophecies of the saints. They have said that in the latter ages of the world, the glories of Saint Joseph will be brought to light; that God will draw aside the veil, which has hitherto prevented us from seeing the wonderful sanctuary of Joseph's soul....
Here is a quote from the encyclical Quamquam Pluries by Pope Leo XIII from Louange de sa gloire:
Thus in giving Joseph the Blessed Virgin as spouse, God appointed him to be not only her life's companion, the witness of her maidenhood, the protector of her honour, but also, by virtue of the conjugal tie, a participator in her sublime dignity. And Joseph shines among all mankind by the most august dignity, since by divine will, he was the guardian of the Son of God and reputed as His father among men. Hence it came about that the Word of God was humbly subject to Joseph, that He obeyed him, and that He rendered to him all those offices that children are bound to render to their parents. From this two-fold dignity flowed the obligation which nature lays upon the head of families, so that Joseph became the guardian, the administrator, and the legal defender of the divine house whose chief he was. And during the whole course of his life he fulfilled those charges and those duties.
The month of May begins with a feast of Saint Joseph. It is significant that the commemoration of Saint Joseph both precedes and follows the heart of the whole liturgical year: the glorious Pasch of the Lord. We celebrated Saint Joseph on March 19th; he returns to us again today.Saint Joseph is never far from the Blessed Virgin Mary, his immaculate spouse and, yes, his best friend, the friend of his heart, the love of his life, the unfailing cause of his joy in the midst of anxieties, hardship, and sorrow. Saint Joseph participated intimately in all those sorrows of hers that announced and prefigured the mysteries of Christ's passion, death, and burial: the prophecy of Simeon, the flight into Egypt, the disappearance of the boy Jesus in Jerusalem. If you would empathize with the Heart of Mary, go to Joseph.