Letter indicating Second Anointing was given in Nauvoo.
Samuel James, Letter to Sidney Rigdon, 28 January 1845, in Latter Day Saint's Messenger and Advocate 1, no. 9 (March 1, 1845): 130
Mr. [William] Marks then told me that he was present when the twelve were ordained, and Brigham Young was ordained under Hyrum Smith, to the office of prophet, priest, and king, and Brigham ordained the rest of the twelve to the same office. And that he (Marks) was ordained to the same office under the hands of Joseph Smith.