Sullivan Line

Sullivan Line
Corner monument north of Sheridan, Missouri, showing the start of the Sullivan Line. The pink monument commemorates the Honey War.

The Sullivan Line originally marked in 1816 forms three quarters of the border between Missouri and Iowa and an extension of it forms the remainder. The line was initially created to establish the limits of Native American territory (they would not be permitted south of it); disputes over the boundary were to erupt into the Honey War.