Histories of religion and the American Civil War have, understandably, emphasized differences between Northerners and Southerners. White Northerners had a wide range of opinions about slavery’s morality, but they tended to share a quasi-sacred view of the American nation. Therefore, they deplored the Confederate attempt to divide that nation.

White Southerners, meanwhile, generally agreed that the Bible permitted slavery. Some Southern leaders portrayed the South as a model Christian society with an orderly economy, led by slave-owning patrons and founded on a “mud-sill” class of enslaved laborers.

The “theological crisis” of the Civil War, as historian Mark Noll has observed, resulted from the North and South’s inability to arrive at a biblical consensus about the permissibility of chattel slavery (a system in which masters treat slaves as transferable property). And thus, as Lincoln’s Second Inaugural Address intones, “The war came.”

These classic North-South divisions don’t explain, however, why Christians in the North were bitterly divided among themselves too. Obviously, their division wasn’t as severe as what cleaved South from North. But outbreaks of violence between Northerners during the war, and pro-Confederate sentiment among Northern “Copperheads,” showed that the differences could be sharp.

Richard Carwardine’s Righteous Strife: How Warring Religious Nationalists Forged Lincoln’s Union shows how these “warring religious nationalists” shaped the North during the Civil War. Carwardine is one of this generation’s top scholars of religion and politics in the antebellum and Civil War eras. I’ve regularly recommended his Lincoln: A Life of Purpose and Power as an excellent book on Lincoln’s religion.

Searching for Parallels

Many Americans today assume that during the Civil War, white Northerners largely supported emancipation. As Carwardine shows, that was simply not the case. Many Northern Protestant and Catholic leaders, as well as rank-and-file Unionists, adamantly opposed abolitionism, seeing it as fanatical and reckless.

Although Lincoln’s own views are debated, he certainly made clear when he was elected president in 1860 that he didn’t intend to touch slavery in the South. He had no constitutional power to do so, he said.

In 1860, slavery was widely understood to be subject to state, not federal, jurisdiction. The war and Lincoln’s role as commander-in-chief of the armed forces changed that legal understanding.

More than a year into the war, Lincoln still stated publicly that preserving the Union was his preeminent aim. If he could preserve the Union without freeing the slaves, he was content to do so. Lincoln also made periodic comments, conventional for all but the most radical politicians, that he believed the white race should have the dominant place in American society. Still, Lincoln eventually embraced emancipation, believing that destroying slavery would help the Union win.

Whatever the intent of Lincoln’s Emancipation Proclamation in 1863, the president took a great risk by potentially alienating conservative religious nationalists who wanted to preserve the Union while leaving slavery alone. By “conservative,” Carwardine means nationalists who wanted to “conserve” the Union largely intact. By the book’s end, Carwardine also proposes parallels between the conservative Christian nationalists of the 1860s and those of the early 21st century.

This stilted comparison is the least helpful part of Righteous Strife. We already have more than enough books that clumsily try to discover the religious origins of Trumpism in various Christian movements in the past.

Celebrating a Specific Nationalism

Yet Carwardine also more intriguingly argues there can be a good kind of Christian nationalism, if its adherents support moral policies. Obviously, Carwardine prefers Christian nationalists in the 1860s who thought the nation should abolish slavery because America was Christian. They insisted that slavery violated the nation’s God-given mission.

Carwardine offers his most thoughtful comments on Northern figures, including Lincoln, who moved from conservative (anti-emancipationist) nationalism toward abolitionist nationalism during the war. Some of Carwardine’s most astute observations in this vein are about Princeton Seminary theologian Charles Hodge.

Hodge was arguably the era’s greatest defender of scriptural authority against higher biblical criticism. But on slavery, he was a moderate. Hodge had many Southern students and was a slave owner himself. From a plain reading of Scripture, Hodge could find no rationale for condemning slavery “in the abstract.” The Bible largely seemed to accept the institution and didn’t comment directly on its morality.

Hodge was arguably the era’s greatest defender of scriptural authority against higher biblical criticism. But on slavery, he was a moderate.

Yet Hodge was sharply critical of the South’s chattel slavery, riddled as it was with abuse and corruption that violated biblical ethics. Many slave masters were willing to break up slave families with the stroke of a pen. Many whites resisted teaching slaves to read the Bible, fearing that stories such as the exodus would give enslaved people subversive notions about liberty.

Hodge also exhibited typical nationalist reverence for the American Union, believing that the Confederacy’s crusade to separate from the United States was paranoid and foolish. Like many Northern Christians, Hodge opposed secession precisely because he was a conservative.

Although Hodge had long opposed abolitionism, he came to support Lincoln’s Proclamation. He affirmed Lincoln’s notion that emancipation was an essential wartime measure needed to preserve the Union.

Hodge still warned that if emancipation became the ultimate aim of the war, it would sow dissension among Northerners and foment radical social revolution. But Hodge saw the Proclamation as a limited executive action. Its abolition of slavery didn’t apply to the border states remaining within the Union, or to parts of the Confederacy that lay under Union military control. (Wholesale emancipation came later, in the Thirteenth Amendment of 1865.)

In other words, the Proclamation was conservative. This conclusion allowed Hodge to transform himself from an anti-emancipation nationalist to an emancipationist one. Most of Hodge’s Old School Presbyterians followed his lead. The war taught them that Southern proslavery fanaticism had only precipitated “rebellion, war, and bloodshed.” Therefore, slavery must go.

Pursuing a More Perfect Union

In his conclusion, Carwardine makes patronizing and unnecessary comments about today’s “white evangelical churches” and their “studied whiteness.” This may alienate some Christian readers. I still think, however, that such readers can find useful content in Righteous Strife related to the “Christian nationalism” debate.

Since 1776, Christian ethics has deeply influenced American culture and law. But the federal Constitution didn’t make America a “Christian nation” in any formal sense, preferring instead to prioritize “free exercise” of religion. So where does this leave American moral reform based on Christian ideals?

Christian ethics has deeply influenced American culture and law. But the federal Constitution did not make America a ‘Christian nation’ in any formal sense.

Polemicists have cited Christian values on both sides of almost every major political debate in American history. We may question how many of those appeals have been substantial and sincere. Yet a type of cultural and theological Christian nationalist argument has undergirded every noble reform movement in America’s history, from abolitionism to civil rights to the pro-life cause.

Whether or not the term “Christian nationalism” is redeemable, Righteous Strife reminds readers of the great good that has come when leaders such as Lincoln have appealed to the nation’s providential calling and to the “better angels of our nature.”