What differentiates Montana and the Dakotas?

[Ban my account ffs!]

Montana had a huge influx of Southerners at one point, that propelled a lot of early Democratic strength in the state. Whereas the Dakotas, or at least North Dakota in particular was settled by a combination of Yankees, Germans and some Scandanavians and thus favored the Republicans (save for daliances with the Populists, TR and the FDR in the Great Depression), until about the 1950's, when the Democrats began to gain strength.

Yankees, Germans, and some Scandinavians?

North Dakota is the most Scandinavian state in the union.  The state is 47% German background, 30% Norwegian, and 5% Swedish.

Irish make up just under 8% and English 4%.

Yankees made up a very small part of the settlement there.  It was almost exclusively Germans and Scandinavians.

And while they were Republican, just as in Minnesota... there was a strong progressive streak that led to the rise of the non-partisan league which was Republican aligned and then later aligned with the Democrats... which is why the Democratic Party of North Dakota is called the Dem-NPL party to this day.

And to think that North Dakotan Republicans are anything like national Republicans would be a mistake.  They operate much more like a Christian Democratic party of Europe than anything like the modern GOP.

[Ban my account ffs!]

My point was that "yankees, Germans, and some Scandinavians" was just wrong.  The state was settled by huge waves of immigrants coming from Germany and Norway with some Swedes, Irish, and minor amounts of other.

But it was not like Minnesota.  Minnesota began to be settled by yankees as early as 1820 when Fort Snelling was established and much of the earliest settlement was from French fur traders and yankees who then were quickly overwhelmed by waves of Germans and Scandinavians later on.

North Dakota was almost completely unpopulated by whites as late as 1870.  By that point, the main immigrant waves were coming in from northern Europe and they quickly settled the region, especially the eastern part of North Dakota.

There was very little "yankee" culture in the state.  It was a culture of immigrant Norwegians, Swedes, and Germans from the beginning.  And the Norwegians kinda took over everything the same way they did in Minnesota, despite not being the majority.

Here's a catchy little song from a Swede in North Dakota at the time that encapsulates the culture:

I’m a Svede from Nort’ Dakota,
Vork on farm for half a year,
I vent down to Minneap’lis
All to see da big State Fair.
I vent down to Seven Corners
Vere Salvation Army play,
Dere a voman come up to me,
Dis is vat the voman say.

She say, “Vill you vork for Yesus?”
I say, “How much Yesus pay?”
She say, “Yesus don’t pay notting.”
I not vork for him today.

I voke up da very next morning,
In da town dey call Saint Paul;
I voke up vit’ an awful headache;
Tink I got some alcohol.