In 1839, Missouri and Iowa Territory found themselves in a border dispute over the northern border of Missouri and the southern border of the Iowa Territory. Both sides claimed the same nine-and-a-half mile strip of land.

Colonel John C. Sullivan surveyed Missouri’s northern border in 1816 which became known as the Sullivan line. A description of this line was in Missouri’s constitution, “the northern border of the state began at rapids on the Des Moines River.”

Because of multiple Indian treaties, and the giving and taking of tribal lands, another survey was done in 1837 by Joseph C. Brown who followed the description as stated in the constitution. But the rapids used in the Sullivan survey were not the same rapids used in the Brown survey. In 1838, the Missouri legislature declared this new survey the northern border of Missouri even though it contained almost 2,600 square miles more land. This was the land that was claimed by Iowa.

When Missouri and Iowa almost went to war over ownership of this strip of land, both sides were willing to allow the US Supreme Court to settle the dispute.

State of Missouri v. State of Iowa was heard by Chief Justice Roger B. Taney and eight associate justices in 1849. Associate Justice John Catron delivered the unanimous opinion.

That decision was based on several factors. The Court wanted to know to what degree the Sullivan Line had been used in the past. It was found that over 15 Indian treaties had recognized the Sullivan Line. Federal and territorial land agencies, as well as Missouri land sales agents, had all used the Sullivan Line as Missouri’s northern border. And it was noted that the US had respected the Sullivan Line in establishing the borders of the various territories north of Missouri.

A second factor involved locating the “rapids of the Des Moines River.” Brown’s survey mentioned ripples, falls, and shoals, but no rapids.

When Missouri’s constitution was reviewed, they found reference to the Sullivan Line and the rapids on the Des Moines River.”

The Court held that Missouri’s northern border was the 1816 Sullivan Line and the strip of land in question was actually the southern border of Iowa.

Elizabeth Davis was born and raised in Cooper County, Missouri, and has written HISTORICALLY YOURS for the Boonville Daily News since April 2008, She has covered the War Between the States, US history, and Cooper County history. In celebration of Missouri’s upcoming Bicentennial, she syndicated her column statewide in September 2018 and encourages readers all over the Show Me State to submit topic suggestions for future columns to HistoricallyYours.davis@gmail.com