It was created in 1969 when it traded route numbers with Iowa 15 in Van Buren County.

Iowa 23 began in downtown Ottumwa underneath a bridge on which US 63 passed overhead.

The two directions converged at an intersection with McPherson Street, which is located next to a level crossing of the Dakota, Minnesota and Eastern Railroad.

[2] As Iowa 23 left Ottumwa, it traveled northwest on a two-lane highway with narrow shoulders.

The tracks cross over to the western side of the river halfway between Ottumwa and Chillicothe.

[11] Box culverts on the section between Ottumwa and Eddyville were built in late 1994 and construction began in earnest in early 1995.