The archangel Gabriel told Mary who was carrying Jesus in her womb to go to her cousin Elizabeth's house. It was a long and arduous journey but Mary went obediently and joyfully.
When Mary arrived at Elizabeth's house, the baby inside of Elizabeth, St. John the Baptist, jumped. He did this in that he recognized the baby inside of Mary as his Lord and God. Elizabeth also recognized at that moment that Mary was the mother of the son of God.
Because Elizabeth was a great deal older than Mary, the Blessed Mother stayed for three months to help her. Elizabeth's husband Zachary was cured of his affliction as a mute and was able to speak again. St. John the Baptist was cleansed of original sin while still in the womb. The Holy Spirit blessed both families abundantly during the Visitation.