After Sullivan died in 1830, the Sullivan Line was extended in the west to the Missouri River in 1836 as the U.S. government in the Platte Purchase bought all the land west from the Indian Boundary Line and then permitted Missouri to annex the land. As part of the purchase, Missouri wanted the Sullivan Line resurveyed.
After Sullivan passed away in 1830, the Sullivan Line was extended westward to the Missouri River in 1836 as a result of the U.S. government acquiring all land from the Indian Boundary Line through the Platte Purchase and allowing Missouri to annex it. As part of this acquisition, Missouri sought for the Sullivan Line to be resurveyed.