Born in Pennsylvania, Whitmer moved with his parents to New York, where he married Elizabeth Schott on September 29, 1825.

Whitmer’s younger brother, David, became a close associate of Joseph Smith.

In June 1829, Jacob Whitmer joined his brothers in signing a statement testifying that he personally saw and handled the golden plates said to be in Smith's possession.

He then settled in Caldwell County, Missouri where he served on Far West's high council and received an elder’s license from the church in December 1837.

[2] Whitmer settled finally near Richmond in neighboring Ray County, where he worked as a shoemaker and a farmer.