The Mississippi and Missouri Railroad (M&M Railroad) was the first railroad in Iowa. It was chartered in 1853 to build a line between Davenport, Iowa, on the Mississippi River and Council Bluffs, Iowa, on the Missouri River. The railroad was the first west of the Mississippi river to join by bridge to the East. It played an important role in the construction of the First Transcontinental Railroad. The competing Cedar Rapids and Missouri River Railroad actually became the first Iowa railroad to reach Council Bluffs from the Mississippi River. Thomas C. Durant, vice president of the Union Pacific Railroad, owned stock in both.
The Rock Island Line bought the M&M on July 9, 1866, and completed its line to Council Bluffs in 1869 and extended the Muscatine/Washington Line to Leavenworth, Kansas. The merged railroad was called the Chicago, Rock Island and Pacific Railroad, a name it kept until it was dissolved in bankruptcy in the 1970s.