Is there really a need for a north AND south dakota? Can't we just make it a Dakota?
Funny story behind that, the capital of Dakota Territory was Bismarck at the time of the push for statehood.
Most of the southern population that had political pull was in what would now be southeastern South Dakota, so like Vermillion and Yankton. You can lump Sioux Falls in there too, obviously.
During that time, the railroads had evolved into the main arteries of travel and trade, as opposed to water i.e. via the Missouri River.
The western railroad cities had a decision to make, and most cities wanted to retain morr of a direct east/west line as possible. North Dakotans fell more under the sphere of influence of the twin cities... a general cultural and commercial connection that exists to this day.
While South Dakotans felt more directly tied to the cattle markets of Chicago and Omaha/Council Bluffs, via the direct existing corridors through Iowa, ironically. The remnants of this is where we get the corridors of Highways 3 and old 20, and I-29 along the iowa side of the river, respectively.
Not to mention there was little existing modern infrastructure and even less incentive to build new ones to extensively and profitably connect the political and power centers of the North and South Dakota in a meaningful way, at least compared to the incentives to do so to their respective Easts.
Not to mention having two Northern states join as opposed to one was always an attractive selling point in Washington post-Lincoln. As well as helping to control 'The Indian Problem', as it was called at the time, by dividing and thus doubling their efforts to that end. (I'm half Oglala Lakota from the Pine Ridge Indian Reservation...hence the name)
*per Google AI*
There are two Dakotas because the vast Dakota Territory was split into North and South Dakota in 1889 for political and practical reasons, primarily for increased representation in Congress (more Republican senators), resolving regional disputes (capital location, economic differences), and because the population centers were far apart, making one large state difficult to manage. President Benjamin Harrison signed the statehood proclamations simultaneously, intentionally shuffling the papers so it's unknown which was admitted first, though North Dakota is usually listed first alphabetically.