Between 1861 and 1865, the American Civil War drove unprecedented demand for mass-produced canned foods, particularly in Northern states where firms like Gail Borden and the Chicago meatpacking industry supplied millions of cans of condensed milk, meat, and vegetables to Union armies. The U.S. government became the largest single purchaser of canned goods in the world, accelerating technological improvements in canning that made processed food cheaper and more widely available after the war. This military-driven industrialization of food processing established the infrastructure and consumer familiarity with canned foods that would later enable the entire processed and junk food industry.

Walt Whitman, who served as a nurse in Union Army hospitals in Washington, D.C., documented soldier rations including canned goods in his poetry and prose notebooks, using the industrialized food of war as a counterpoint to his celebrations of natural abundance. The contrast between canned provisions and fresh food became a recurring motif in war poetry, from Whitman's Civil War writings through World War I poets like Wilfred Owen, who used tinned food imagery to convey the dehumanizing conditions of industrial warfare.