Of the many people that ventured into southwest Iowa, and northwest Missouri, in the early years after the Platte Purchase of 1836, one of the first was Major Stephen Cooper.  He and Colonel Boon and Major Bancroft were commissioned to locate and mark the northern boundary line of Missouri.

As a result of their work, the northern Missouri boundary line was set at what is now approximately a mile and half south of Sidney.  This boundary line was disputed by the states of Iowa and Missouri,  with Iowa arguing that the line should be further south.  This dispute over the 8 mile wide strip of land from the Missouri River all the way over to the Mississippi River became known as the 'Honey War' because the land was agriculturally valuable, and was especially well known for its honey production. The argument was finally decided by the U.S. Supreme Court in 1849, when it sided with Iowa placing the southern boundary of Iowa at it's current location.

Around 1836, Major Cooper was appointed Indian agent for the Council Bluffs area and by the spring of 1839 settled three or four miles southwest of Sidney under the edge of the bluff on the farm  owned by Knox brothers. He facilitated trading with the Pottawattmie and Omaha tribes in the area at that time. (Source: Historical notes of Mabel Bridges; as reported by Walter Farwell).   

In 1842, since this part of Iowa was still considered Holt county Missouri, Major Cooper ran for and was elected as state legislature to Missouri for Holt county. In 1845, Major Cooper was asked to join the John C. Fremont expedition to California.   A year later, upon his return, he began planning to move with his family to California. This began another episode in his life in which he was exploring new territory and was one of the first U.S. citizens in that area thereby opening it up to the many settlers who would soon follow his lead.

Major Cooper had a very eventful life before and after his short stay in southwest Iowa.  He eventually moved to Colusa, California; where he died in 1890.

To get a full appreciation for this early settler of Fremont County you might want to read his obituary from 1890. He also wrote an autobiography in 1888 which is extremely detailed and most interesting.