John James Oltmanns, Assistant in the Coast Survey, assimilated rank of major in the Union Army during the Civil War

John James Oltmanns, Assistant in the Coast Survey, assimilated rank of major in the Union Army during the Civil War. Served on staff to General William B. Franklin during the Red River Campaign, with Sheridan at Cedar Hill, and early in the war with Porter on the Mississippi River. Wounded on a reconnaissance of the Pearl River, he died 5 years after the war from complications.