(lē'bər), 1798–1872, German-American political philosopher, b. Berlin. Ardently patriotic, he enlisted in the Prussian army and fought and was wounded at the battle of Waterloo. On his return to Germany he joined the Turnverein movement. In the suppression of student organizations in 1819, Lieber became suspect for his liberal ideas and was harried by the police for the remainder of his life in Germany; he was twice imprisoned. Not permitted to attend a Prussian university, he obtained a degree at Jena. In 1826 he fled to England. He went to Boston in 1827 to teach Jahn's system of gymnastics. From his idea of translating the Brockhaus encyclopedia into English sprang the first edition of The Encyclopaedia Americana (13 vol., 1829–33), which he edited. Lieber was professor of history and political economy (1835–56) at South Carolina College (now Univ. of South Carolina). While there he wrote the books that established his reputation as a political philosopher—A Manual of Political Ethics (1838), Essays on Property and Labor (1841), and On Civil Liberty and Self-Government (1853). He taught at Columbia from 1856 until his death. During the Civil War, he prepared for the Union government Instructions for the Government of Armies of the United States in the Field, known in its final form as General Order No. 100, issued in 1863. It was the basis for later efforts to codify the international law of war. After the Civil War, Lieber joined the radical Republicans.
- See biography by F. Freidel (1948, repr. 1968);.
- Lieber's Code and the Law of War (1983). ,