Art. 43. Therefore, in a war between the United States and a belligerent which admits of slavery, if a person held in bondage by that belligerent be captured by or come as a fugitive under the protection of the military forces of the United States, such person is immediately entitled to the rights and privileges of a freeman To return such person into slavery would amount to enslaving a free person, and neither the United States nor any officer under their authority can enslave any human being. Moreover, a person so made free by the law of war is under the shield of the law of nations, and the former owner or State can have, by the law of postliminy, no belligerent lien or claim of service.
Francis Lieber led a colorful life. Born in Berlin in 1798, he enlisted in the Prussian Army in 1815 and was wounded at Waterloo. Unable to attend a university in Berlin due to his membership in a Liberal group that opposed the Prussian monarchy, he attended Jena University and, a brilliant student, completed his dissertation on mathematics in four months in 1820. He took time out from his academic career to fight in the Greek War of Independence in which he was severely wounded. He served as a tutor for the son of the Prussian ambassador in Rome for a year and wrote a book about his experiences in Greece. Receiving a royal pardon, he returned to Prussia only to run afoul of the authorities again for his Republican beliefs. Imprisoned, he took advantage of the time to do what any good Romantic of his generation would do, he wrote a book of poetry, Songs of Wine and Bliss.
After his release he fled to England, where he supported himself by acting as a tutor. Meeting his future wife and marrying her, the Liebers left the Old World to start a new life in the New World in 1827. There Lieber embarked on an academic career. In Boston he achieved notoriety for opening a school which gave instruction in swimming, a first in America. He edited a 13 volume Encyclopedia Americana. From 1833-1835 he resided in Philadelphia while preparing a plan of education for Girard College. In 1835 he began a sojourn of 21 years duration at the University of South Carolina teaching history and political economics. He retained an interest in Germany, and returned for a few months after the revolution of 1848 although his hopes that Germany would take the Liberal path he favored were quickly dashed.
From 1856-1865 he was professor of history and political science at Columbia. In 1860 he was also appointed a professor of political science at the law school at Columbia, a post he would hold until his death in 1872.
The coming of the Civil War tragically divided Lieber’s family, just as it divided the nation. One of his sons fought and died for the Confederacy, while his other two sons fought for the Union. Lieber himself was a staunch advocate of the Union and an opponent of slavery. He founded and headed the Loyal Publication Society that wrote scholarly pro-Union propaganda during the War. He first met Lincoln at the White House in 1861 to confer upon him an honorary degree from Columbia. Thereafter he was called to Washington frequently to consult with Lincoln, Stanton and Seward on questions of international law.
During his academic career Lieber had written many books and articles on law, politics and history that had given him an international reputation. It is therefore not surprising that Lincoln turned to Lieber to draft a code of Law to govern the Union forces during war-time. The Code was promulgated in General Order 100 on April 24, 1863.