In August 1857, Jacob Hamblin, the newly appointed president of the Southern Indian Mission selected Leavitt and Samuel Knight as his counselors. In early September 6th Samuel Knight brought orders to Fort Clara , probably on Sunday, September 6, to muster the militia to Mountain Meadows. Leavitt, Knight and other Indian intepreters from Fort Clara and Southerners from neary Washington traveled north from these southern settlements on Monday, September 7th (the day of the First Ambush), meeting John D. Lee between ten and sixteen miles south of Mountain Meadows. The next day they moved up to the Meadows and encamped in the "southern" camp, separate from those from Cedar City detachment.
Leavitt's role on the day of the final massacre was to follow orders: "Mormon's do your duty."