Theodor Hilgard (1790-1873) was born in Bavaria, educated in Germany and France, but immigrated to the United States in 1836, settling with his wife, five daughters, and four sons, in the German colony at Belleville, Ill. Hilgard engaged in farming and real estate promotion, while encouraging his sons in their educational pursuits. One son, Julius Erasmus Hilgard (1825-91), studied geology and later became chief of the United States Coast Survey. In 1849, Eugene Woldemar Hilgard (1833-1916), another son, returned to Germany where he eventually received a Ph.D. in geology. He later served as Director of the State Geological Survey of Mississippi, and taught at the University of Michigan and the University of California, Berkeley.
This collection mainly contains published works by and about the Hilgard family, including "Geschichte der Auswanderung Einer Deutschen Familie" ("The Story of the Emigration of a German Family") by Theodor Hilgard; Memoir of Julius Erasmus Hilgard, 1825-1891 (1903); an article about Eugene Hilgard in the California Alumni Weekly (Apr. 18, 1914); and Eugene Hilgard's autobiography. This autobiography includes three sections: "Biographical Memoir of Eugene Woldemar Hilgard," "Home Life in Illinois," and "Botanical Features of the Prairies of Illinois in Ante-Railroad Days," the last being a semi-scientific treatise. The collection also contains correspondence between Theodor Hilgard, in Belleville, and his mother, Madame Maria Dorothea Engelmann Hilgard, in Bavaria.
Eugene Hilgard donated the collection to the Library in 1915.