American Frontier
–Fur trade
link fur trappers, Platte Valley
beaver and river otter should be linked here rather than later. (T/C//WP:CHICAGO/WP:FOUR)  

–Settlers and pioneers
What does this mean: the western approach of the First Transcontinental Railroad was a ferry ride across the Missouri
Link Independence and clarify its relation to the river.
naturally and "Had to be" in para 4 sound POV (T/C//WP:CHICAGO/WP:FOUR)