Why is Indiana so damned Republican?

[Gustaf]

I find it funny that Indiana voted with the South against the Midwest and Northeast back in the Gilded Age, just like today (different margins, but still).

[Gustaf]

The rural areas are definitely the reason.  More than 70% of Indiana's counties have less than 50,000 people (Group A), and more than 80% have less than 100,000 (Group B).  Group A counties make up 30% of Indiana's population and Group B makes up an astounding 41% of Indiana's population.  Given the fact the rural voters come out in higher numbers than urban voters, it becomes clearer why the state has such strong Republican trends.

That makes sense in current terms, but why were they so strongly Republican back when Republicans were seen as the party of elitist north-eastern Business interests and Democrats were seen as the rural farmer's party?

That's not quite the way it was.  Yes the GOP had the business interests but also dominated virtually every rural area in the north and midwest.  The Democrats just had the rural south.

Furthermore, that's not quite how Indiana voted. It voted Democrat on several occassions during the Gilded Age.

Edit: in 1876, 1884 and 1892. That is, every time the Democrats won the election (counting 1876 as a Dem win). It was the only Midwestern state to vote Democrat during this time.