Quoted from the Catholic Diocese Of Brooklyn [1]:
The Visitation of the Blessed Virgin Mary is the visit of Mary with Elizabeth as recorded in the Gospel of Luke (Lk 1:39-56). It is also the name of a Christian feast day commemorating this visit, celebrated on May 31 in the West (July 2 in calendars of the 1263-1969 period and in the modern regional calendar of Germany) and March 30 in the East.Mary visits her relative Elizabeth; they are both pregnant. Mary is pregnant with Jesus and Elizabeth is pregnant with John the Baptist. Mary left Nazareth immediately after the Annunciation and went “into the hill country…into a city of Judah” (Luke 1:39) to attend her cousin Elizabeth. There are several possibilities as to exactly which city this was, including Hebron, south of Jerusalem, and Ein Karem. The journey was about 100 miles, and Elizabeth was in the sixth month before Mary came (Luke 1:36). Mary stayed three months and departed just before John was born.Catholics believe that the purpose of this visit was to bring divine grace to both Elizabeth and her unborn child. Even though he was still in his mother’s womb, John became aware of the presence of his Divine Saviour; he leapt for joy as he was cleansed from original sin and filled with divine grace. Elizabeth also responded and recognized the presence of Jesus. Thus Mary, now for the first time, exercised her function as mediatrix between God and man.Elizabeth remarks to Mary: “And she spoke out with a loud voice, and said, Blessed [art] thou among women, and blessed [is] the fruit of thy womb. And whence [is] this to me, that the mother of my Lord should come to me? For, lo, as soon as the voice of thy salutation sounded in mine ears, the babe leaped in my womb for joy. And blessed [is] she that believed: for there shall be a performance of those things which were told her from the Lord (Luke 1:42-55)”It is also at this point, in response to Elizabeth’s remark, that Mary proclaims the Magnificat (My soul doth magnify the Lord), (Luke 1:46-55), for which reason this canticle had traditionally been reserved for this feast day.