Theodore R. Ditterline (December 19, 1816 - March 10, 1883) was an American schoolteacher, clerk, and cartographer. Born in Pennsylvania, Ditterline appeared in the 1850 U.S. Census as Theodore Deterline, age 33, living in Gettysburg, Pennsylvania, with his mother, Jane Deterline, and working as a teacher. In the 1860 U.S. Census, Ditterline still resides in Gettysburg with his mother but works as a clerk, and they have both changed the spelling of their last name to Ditterline. He lived in Gettysburg at the time of the American Civil War. In 1863 he published a landmark map of the Battle of Gettysburg in a pamphlet titled Sketch of the Battles of Gettysburg with an Explanatory Map. Ditterline appears in the 1871 Washington, D.C. City Directory, and he worked as a clerk in the Treasury Department. In 1874, he was still working in Washington per the City Directory, but as a clerk in the War Department. In 1881, Ditterline worked as a clerk in the Engineering Department of the War Department. Ditterline died in 1883 and was buried in Evergreen Cemetery in Gettysburg.