These antique signals were gradually replaced with more modern signals in the 1970's due to government-required modernization and a lack of spare parts. Chariton was also served by the Chicago, Rock Island and Pacific Railroad (Rock Island) which came up north from Corydon on the southeast side of Chariton where it crossed over the CB&Q on its way north and west to Des Moines. The Rock Island line went bankrupt in 1980 and was purchased by the Chicago & Northwestern Railroad. The Chicago & Northwestern Railroad was purchased by the Union Pacific in 1995. This line is now known as Union Pacific's Spine Line. It was purchased as a more direct line between Kansas City and Minneapolis. It has seen a marked increase in traffic since the Chicago & Northwestern merger with Union Pacific. The last passenger train on the old Rock Island system through Allerton was the Plainsman from Kansas City to Des Moines and Minneapolis. It was discontinued in 1970.