A native of New Hampshire, he joined Jason Lee as a missionary at the Methodist Mission in the Oregon Country in 1836.

[1] Leslie, his wife Mary A. Kinney, and three daughters sailed around Cape Horn and arrived in Oregon on the Sumatra on September 7, 1837.

[1] Once in Oregon Lee assigned Leslie to be a magistrate for the area south of the Columbia River.

[3] After Lee returned Leslie helped to start a branch mission with William H. Willson at Nisqually on the Puget Sound in modern Washington state.

[1] 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.

[4] This meeting was held at Leslie’s home, and was in part a response to the death of pioneer Ewing Young.

[6] Although only a few decisions were ultimately made (election of Dr. Ira L. Babcock as a supreme judge to deal with the Young estate), this was the first of the Champoeg Meetings that two years later would lead to the creation of the Provisional Government of Oregon.

[1] Without his wife to assist in raising the children, Leslie decided to take them to a mission in Hawaii where there was a school for them.

[1] As they waited to leave Astoria on the mouth of the Columbia River, one of the daughters (Satira age 15) left the ship and married Cornelius Rogers.

[1] Leslie then continued on to Hawaii where he left the two remaining daughters Mary and Sarah at a boarding school.

[1] However, by this time the mission was beginning to be closed in Salem for a lack of natives to convert due to disease that had decimated the original inhabitants[10] of the region.