What lies north of the territory ceded to the us in the convention of 1818?

On March 6th, the congress approved an act permitting the people of Missouri to form a constitution and state government; - by the 8th section of the convention, slavery is forever prohibited in all the territory ceded by France to the United States under the name of Louisiana, which lies north of 36 degrees, 30’ north latitude, not included in the contemplated state.