Science  /  Study

New Estimates of US Civil War Mortality from Full-Census Records

The Civil War was the deadliest conflict in US history. However, incomplete records have made it difficult to estimate the exact death toll.

State-Level Estimates of Civil War Deaths

This report’s main contribution is that we are able to provide reliable estimate of the Civil War’s death toll at the state level using the migration-adjusted census comparison method. One limitation is that our ability to calculate credible estimates is hampered in frontier regions that were settled around the mid-19th century, where census records are especially unreliable. All in all, we are able to accurately estimate the war’s death toll in core states that were settled before 1830 and whose populations comprised 90% of the US’ native-born white fighting-age males. This includes 13 of the 18 nonenslaved Northern states (what we term Old North), 8 of the 11 slaveowning Confederate states (Old South), and the remaining five slaveowning states, including West Virginia, which did not join the Confederacy (Border States). The states in each grouping are listed in Fig. 1.

In Table 2, we present the excess mortality estimates for the three regions: Old North, Border States, and Old South. Combining these migration-method bloc estimates with our national count from the sex-differential method suggests that these regions accounted for 93% of all Civil-War deaths among military-age NBWM (460,032/496,332).

The difference in death tolls across regions demonstrates powerfully how much deadlier the Civil War was for the Confederacy than the Union. Although the core of the Confederacy had fewer than one-third as many military-age NBWM as the core of the Union, states at the core of the Confederacy suffered almost as many casualties (192,160 deaths in the Old South vs. 229,803 in the Old North). This translates into an excess mortality rate of 13% in the Confederacy against only 5% in the Union.

If we apply the 13% excess mortality rate to the remaining three Confederate states not in our analyses and include excess mortality from the Border States and foreign-born fighters who fought for the Confederacy then the total estimate of deaths in the Confederacy would approach 300,000. Doing the same for the Union states would bring the death tally there to more than 400,000. Combined, these totals match the national tally of 698,000 deaths reported earlier.

In Fig. 1, we present the state-level estimates of war-related excess mortality among military-age NBWM. This figure further illustrates the disproportionate impact of the war on the Confederacy. While seven of the eight Old South states saw at least 10% of their military-age NBWM killed, only one Northern state, Illinois, experienced comparable mortality. The migration-adjusted method permits estimates of war-related deaths at the age cohort level in each state. When examining excess mortality for the different age cohorts, we find that in most Confederate states around 20 to 33% of NBWM aged 15 to 34 in 1860 perished in the war. In the Northern and border states the same age cohorts suffered mortality of below 10% in all but a handful of states.