Indiana - The Southern State in the Midwest

Well, except for Missouri (which wasn't part of the Northwest Territory).  Here's Fiverthirtyeight on why Indiana is weird:

In 1850, census canvassers started asking Americans where they’d been born, and by looking at state residents who were born in the U.S. (but not in their current state), we can see just how much Indiana stood apart from its neighbors in the Old Northwest. Let’s start with people born in New England, the “Yankees” widely considered to be better educated and more ambitious than their peers. In 1850, only 3 percent of Indiana’s U.S.-born residents hailed from New England. (The Old Northwest average was 10 percent.) Only 20 percent of Indiana’s U.S.-born residents hailed from Mid-Atlantic states such as Pennsylvania and New York. (The Old Northwest average was 42 percent.) But a whopping 44 percent of Indiana’s U.S.-born residents hailed from the South — easily the highest percentage in the Old Northwest, where the average was 28 percent.¹
Just as important as their numerical advantage, the Southerners got to Indiana first and thus dominated its early politics. (At the state’s constitutional convention, 34 of the 43 delegates hailed from below the Mason-Dixon Line.) They created its local culture, shaping everything from what Hoosiers ate to how they worshipped. (Southerners imported their Baptist and Methodist beliefs, and in the 1850 census 60 percent of Indiana churches belonged to those denominations.) More than any other Midwestern state, Indiana ended up with a certain kind of citizenry: white, working-class Protestants with Southern roots.
And the thing is, it never really changed. Consider the wave of immigration that defined America starting in the 1880s. Indiana had always been the least diverse state in the Old Northwest. And yet, even after millions of Europeans arrived by steamship, were processed at Ellis Island, and scattered across the country, Indiana still featured a foreign-born population of just 3 percent. (The Old Northwest average was approaching 20 percent.) Or consider the rise of the modern city. In 1920, Chicago’s population was 2.7 million; Cleveland’s was 800,000. Indianapolis’s, by contrast, was only 314,194. But Indianapolis wasn’t just smaller — it was more provincial, less vibrant, a city with a population that was only 3 percent African-American and 70 percent native-born and white. (In Chicago and Cleveland, the share of native-born whites was about 25 percent.)...
Among its Old Northwestern peers, Indiana ranks last in median family income. It ranks last in the percentage of residents who’ve completed a bachelor’s degree. It ranks first in the share of the population that is white Evangelical Protestant and in the share of residents who identify as conservative. On these and a host of other measures — percentage of homes without broadband internet, rate of teen pregnancy, rate of divorce — you’ll often see Indiana finishing closer to Kentucky or Tennessee than to Ohio or Wisconsin. In other words, you’ll see 200 years of history making its presence known.

Or, to put it another way, Indiana didn't end up with its fair share of Catholics and Lutherans.  Also, not surprisingly, Indiana ranks third amongst states for demographics most like America in the 1950s, just behind Kentucky and West Virginia.