Union Township was settled in the early 1840s, at Sharpe's Grove, but its establishment date is unknown.
Marietta was first settled circa 1844 was a community on the east bank of the Missouri River, southwest of where
Craig is today, near
Lewsiville.
Rush Bottoms Conservation Area is where the settlement used to be. A
schoolhouse named Marietta persisted until at least 1920. A hamlet called
Tarkio, also known as Tarkeo or Big Spring, was located in the northern portion of Union township, about 1.75 miles northwest of Craig, along the
Big Tarkio Creek. The
Kansas City, St. Joseph, and Council Bluffs Railroad was completed through this township in 1869. ==Geography==