The treaty signed by Poweshiek, Keokuk, and a number of the other chiefs of the Sacs and Foxes required the groups of Meskwaki living near what became Iowa City to relocate within a year. It gave Keokuk’s group of Sac two years to relocate.
Although Poweshiek’s group was along the Iowa River, most of the others had settled along the Des Moines River. The treaty called for two mills to be constructed for the Indians.
In 1838 Poweshiek and about thirty warriors accompanied General Street on an expedition to determine the best location of the mills, and find a location for a new Indian Agency office building. The trip was tense—Poweshiek and the others were always on the lookout for their old enemies, the Sioux.
They found a location a few miles east of where Ottumwa now stands to build their new Agency City.
The new Indian Agency building was constructed using slave labor. Iowa was not yet a state, and slavery had not yet been outlawed in the territory.
The Meskaki and the Sac would reside near Agency, and in villages along the Des Moines River for a few more years.
Agency City is now just called Agency and has a population of about 600 people.