The settlement starts to grow.

Other settlers from the east, looking toward Missouri for open space and land to farm, soon began to settle in the area selected by Campbell. They came from Tennessee, like Campbell, from Kentucky and Virginia to a place then known only as Fulbright and Campbell Springs. (William Fulbright, his brothers, John and Levi, and brother-in-law A. J. Burnett, had actually preceded Campbell here.)

By 1835, enough had settled around the natural well that the community was laid out and officially named Springfield. Campbell, who had donated 50 acres of land for the community, had a direct hand in naming it and laying it out. Some say the community was named after a similar town in Tennessee but it's more likely the name was a condensation of its first designation as Campbell and Fulbright Springs. Springfield was incorporated in 1838.

A slow steady growth, including new immigrants from Ohio and Indiana, continued until the Civil War when the new community had a population of 3,563 people.