Sullivan Line

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.

In 1804, in the Treaty of St. Louis the Sac and Fox ceded Missouri north of the Gasconade River (but not their villages on the Mississippi River near Keokuk, Iowa). In 1808, in the Treaty of Fort Clark, the Osage Nation ceded all of Missouri and Arkansas west of the fort (now called Fort Osage in Jackson County, Missouri). The exact boundaries of the treaties were never formally surveyed. Resentments about the treaties caused many members of the tribe to side with the British in the War of 1812. At the conclusion of the war, the tribes in the Treaties of Portage des Sioux reaffirmed the earlier treaties of 1815.

In 1816, surveyor John C. Sullivan was instructed to survey the Osage territory starting 20 WEST of Fort Clark at the confluence of the Kansas River and Missouri River. From the north bank of the river opposite Kaw Point in what is today Kansas City Downtown Airport he was instructed to survey a line 100 miles straight north and then east to the Des Moines River (the Sac and Fox owned the land east of the river). Sullivan’s line going north (the Indian Boundary Line (1816)) was to ultimately form the longitudal line from Iowa to Texas west of which Native Americans were to be removed in the Indian Removal Act of 1830.

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