When the War of the Pacific broke out between Chile and the united forces of Bolivia and Peru, his family moved to Oakland, California, the state where his father had resided previously and retained business interests.

During the 1880s through the 1890s, Washington M. Jacobs managed varied mining interests, and was elected Justice of the Peace of the Tucson Precinct of Pima County in 1887, serving for two years.

After his father's death in 1899, Benjamin Jacobs relocated his mother and younger sisters to Oakland, where nearby, he attended and briefly taught chemistry at the University of California, Berkeley.

Relocating to Washington, D.C., Benjamin R. Jacobs joined the federal agency, the Bureau of Chemistry (now the Food and Drug Administration, [FDA]) of the United States Department of Agriculture, with which he had a long association.

In 1917 a federal war-time food control act was passed when crop failures in Europe laid the burden of feeding the populations of both continents, the British Isles, and the armies of the allies—upon the United States.

Among the personal notes about members of what is now the American Chemical Society, in the November 1920 issue of the Journal of Industrial and Engineering Chemistry, is an announcement that Jacobs was leaving the federal government.

Mueller Company to oversee the nutritional enrichment of their macaroni, noodles, and pasta products as they developed the nationally distributed brand that is still a recognized leader in the food industry.

His research also was reported in other scientific publications of the day, such as the American Food Journal, and he served as the president of the National Noodle and Macaroni Association of America.

After raising his daughters as a single father, he married Margaret Ann Connell of Washington, D.C., who was assistant to Samuel Gompers, the founder of the American Federation of Labor.