Why Non-Slaveholding Southerners Fought

The context of this discussion was the Trump supporters who vote against their economic interests. blindness chimed to quote someone from the turn of the 20th century who observed the same phenomena of exploiting cultural issues to manipulate the poor into voting against their own interests. So I brought up the vast majority of Southern whites who did not own slaves, but gave their lives for the Confederacy and its quest to preserve and expand slavery. Strong disagreement ensued. .

The article makes some good points, as far as it goes, but it's not really an article, it's a transcription of a speech; and I can stipulate the truth of every word in it, and it still doesn't make your point, because it only addresses what the clergy and politicians were saying without ever discussing the actual decision making and reasoning of the soldiers who fought. 

And it was quite likely as true then as it is today, the clergy that get published are the ones preaching in the big city churches to wealthy parishioners, not those preaching in backwater shacks; so we know no more about what poor whites heard in church from this article than we did during last night's happy hour. 

The same is almost certainly true of the politicians, for politicians have always gone where the money is, since the dawn of time, and quite rarely ever where the poor people are, unless they're lost. 

It was also suggested that poor whites fought because they themselves owned slaves, or hoped to one day; but the average salary for a laborer in the South in 1860 was less than a dollar a day (Link: Wages by Industry and Region, page 12, Wage-Rates for the East, West, and South) and the average cost of a slave was $800 (Link: Measuring Slavery in 2016 Dollars). 

Were they exploited? Absolutely. 

Did they fight specifically to defend the institution of slavery? Perhaps, but the posted article is not sufficient to prove as much. 

Then it should be easy to prove. 

James McPherson wrote a book on this called "We were in Earnest." I've read over 200 books on the Civil War.

Soldiers of the "Union" fought for two reasons, though that really depended on where they came from. The Yankees of New England, New York, New Jersey, Pennsylvania and Maryland (which was a slave state) mainly fought to keep the US together as a single country, though there were strong anti-slavery elements from those parts of the country. West Virginia remained part of the US. Kentucky declared neutrality. Tennessee voted to not secede, but the sore losers armed themselves and drove out the "pro-Union" forces, including Andrew Johnson. Secession in Virginia was 52%-48%.

The men of the West, who hated Yankees as much as they hated the traitors, were almost exclusively focused on freeing the slaves. Grant, Sherman, Lincoln and others came from there. The West in those days stopped at Indiana, as a practical matter. The anti-slavery feeling was very strong in the West dating back into the 18th century, that the Northwest Territory agreed to become a part of the US only on the condition that slavery wouldn't be legal in those states.

The title of McPherson's book, which quotes letters and diaries from soldiers from both sides, is taken from a letter from a soldier from Minnesota whose wife wondered why, after serving as a volunteer from 1861-64, he had signed up as a volunteer for another 3 years: "When we said we would fight to free the negro from an unholy bondage, we didn't make that promise lightly. We were in earnest."

John Calhoun on slavery: "Slavery is like the lion of the sea, the noble great white shark, which must forever be moving forward, eating everything in its path, lest it die." The traitors left because they'd lost control of the country. Their war with Mexico only yielded one new slave state, Texas. By the Wilmot Proviso, all new states made from the land taken from Mexico would free states. Congress would be controlled by free states and with Lincoln's election for the first time both Congress and the Presidency were held by a party either opposed to slavery or the spread of slavery. That's why those states seceded. Not because their way of life was threatened, but because they couldn't impose their way of life on the rest of the country.

My guess would be that after 1st Manassas there was a certain percentage who joined "the cause" feeling that their "homeland had been invaded".

What percent of young white men in the South was that?