Oliver Cowdery - First Public Discourse of the Church

On April 6, 1830, the Church was organized in Fayette, New York, and Oliver Cowdery was one of the six original members. It was on that occasion that he was ordained by Joseph Smith to be the second elder of the Church. On April 11th, 1830, Oliver preached the first public discourse given by any member of the Church. This was a miraculous moment in the Restoration—Oliver Cowdery had the honor of being the first to publicly proclaim the restored gospel to the world. Thereafter he was very active as a missionary of the Church during the entire summer and fall of 1830, assisting the Prophet in every way possible.

Fuller account of this event (the complete account as preserved in Church History in the Fulness of Times, Chapter Six):

On Sunday, 11 April, Oliver Cowdery delivered the Church’s first public discourse in the Whitmers’ Fayette home. Many people attended, and that day six people were baptized.