Born in Chicago, Illinois, in 1918, Jacobs moved west at a young age and settled in the Los Angeles area.
[1] After military service during World War II, Jacobs started doctoral study at Johns Hopkins University, but decided to return to UCLA to pursue Western Frontier history under the direction of Lewis Knott Koontz.
[2] Jacobs revised his doctoral dissertation, which had won a prize from the Pacific Coast Branch of the American Historical Association,[3] and published it as Diplomacy and the Indian Gifts: Anglo-French Rivalry among the Ohio and Northwest Frontiers, 1748-1763 (Stanford: Stanford University Press, 1950).
Jacobs was recognized for his scholarship by being selected “Faculty Research Lecturer” at the University of California, Santa Barbara in 1956.
[4] He was also elected President of the Pacific Coast Branch of the American Historical Association in 1976 and won the Western Historical Association’s Award of Merit for a “lifetime of revisionism.”[2] After his retirement in 1988, Jacobs conducted research at the Huntington Library in San Marino, California and published On Turner's Trail: One Hundred Years of Writing Western History (Lawrence: University of Kansas Press, 1994) and The Fatal Confrontation: Historical Studies of American Indians, Environment and Historians (Albuquerque: The University of New Mexico Press, 1996).