May 15, 1829

Susquehanna River, Pennsylvania
Joseph Smith and Oliver Cowdery received the Aaronic Priesthood from John the Baptist. Joseph proceeded to baptize Oliver, after which Oliver baptized Joseph. Joseph was then instructed to ordain Oliver to the Aaronic Priesthood, after which Oliver ordained Joseph.
Sources: 
History of the Church, Joseph Smith, 1:39–44
Winter Quarters

Read peer-reviewed articles about Joseph Smith and other Church history topics from BYU Studies. Visit byustudies.byu.edu.