In much the same way most American homes have different half-filled tubes of sunblock, off-sized batteries, and calculators that can't be thrown away, most American homes have the six following foods. We may not eat them often, or even like them, but we still keep them on hand. They're just part of what make a home a home — even if we forget why. Here, the largely forgotten histories of six American staples. 1. Tuna fish During the 20th century tuna fish was one America's most purchased proteins — but it didn't happen without a dash of ingenuity. In 1903,...