sentences:  Then in March 1838 Leslie was left in charge of the mission while Lee traveled back east again to secure more people for the mission in what would become the Great Reinforcement of 1839.After Lee returned Leslie helped to start a branch mission with William H. Willson at Nisqually on the Puget Sound in modern Washington state.Then in 1840 from August through September David Leslie was in charge of a small group that explored further north, nearly reaching Russian-America to look for other locations for future branches of the mission.