Burrus Carnahan examines how Abraham Lincoln came to issue the Emancipation Proclamation on January 1, 1863. This executive proclamation only affected territory of the United States that was in rebellion against the Federal government. Others had encouraged Lincoln to free the slaves when he took office, while others encouraged him to do it when the Civil War started. Lincoln, though, did not feel that he had the authority. Instead of immediately proclaiming slaves to be free, he carefully examined what powers he had in that regard. Lincoln did not believe that the Constitution, as he and others understood it, gave the president such power. Many Southerners feared that Lincoln would free their slaves, and that was in part why they rebelled against the Federal government. Many in the South and in the North thought that only the states had the power to free slaves.

Carnahan presents the various possible ways that Lincoln could free the slaves legally. It turns out that the president, as commander-in-chief of the armed forces of the United States, could claim powers granted to him from the Law of War. Carnahan explores the history of the Law of War and how it was applied to various situations involving property and slaves, showing that Lincoln realized that freeing the slaves would boost the Union’s cause against the Confederacy with other nations in the world, particularly Great Britain and France. Lincoln feared that another nation, by the Confederacy being recognized as a nation, might send military aid to the Confederacy. Lincoln decided it was therefore in the military interest of saving the Union that he free the slaves, but he could only free those slaves in territories that were in rebellion. This decision seems a bit hollow, since Lincoln and his army could not immediately free the slaves in territories they did not occupy. He felt that the proclamation would encourage slaves to run away and thereby hurt the South’s economy.

Another way the Union could hurt the South was by allowing slaves that were declared “contraband” property to come to the various Union armies in the field and, in this way again, hurt the South’s economy. Carnahan examines this and how other military commanders preceded Lincoln in trying to free slaves. Carnahan’s book makes clear that Lincoln did not casually decide to free the slaves.

While this is an academic book, those interested in information on the famous Emancipation Proclamation will enjoy learning how it came about meticulously. It will also inform readers, if they did not already know, that this did not free all slaves. An amendment to the Constitution later did so, but the proclamation was a first step.

There is neither a bibliography nor illustrations included, but there are numerous endnotes and an index. The book jacket features a photograph of Abraham Lincoln taken by Alexander Gardner in 1863. Act of Justice is highly recommended to those interested in the Civil War, slavery, the Emancipation Proclamation, and Abraham Lincoln.

Burrus M. Carnahan is a professorial lecturer at George Washington University Law School and a foreign affairs officer at the U.S. Department of State. He is the author of the International Law in the United States Court of Military Appeals (1980).