Hilgard is renown as the Father of Soil Science, and the founder of that scientific discipline. Born in Bavaria, he was brought to America as a child. He returned to Europe for university education at Freiburg and at Heidelberg, where he received his Ph.D. in Chemistry in 1853. In 1855, he came to Mississippi as Assistant State Geologist and Professor at the University of Mississippi. He came at the behest of Chancellor F. A. P. Barnard, who was trying to build a great scientific center at Oxford.
Hilgard remained for 18 years, through the drama of the Civil War when he put his scientific talents to the use of the Confederacy. He sought out nitrate and salt sources, and tried to build calcium flood lights for the batteries at Vicksburg. Hilgard was a kind, gentle, patient man of extraordinary intellect, beloved by students and associates. In 1873 he moved to the University of California where his fame grew.
Hilgard was the first to delineate the field of soil science. In that discipline most of the long-used definitions, concepts, physical parameters, standard units, and techniques originated with him. He bridged the gap between theoretical science and practical farming.