Forbes Township was established on March 22, 1871, out of the southern portion of
Nodaway Township A year later, on May 10, 1872, the township's northern boundary changed to match the congressional boundary, resulting in Forbes Township expanding by six sections. The extinct hamlets of
Dallas and
West Union were located in this near the mouth of the
Nodaway River, but they dissipated after the establishment of Forbes; today their location is now in
Andrew County due to the shifting of the Nodaway River. The
Kansas City, St. Joseph, and Council Bluffs Railroad was completed through this township in 1869. ==Geography==