Salt and pepper shakers became popular in the United States in the 1920s after the Morton Salt Company developed magnesium carbonate as an anti-caking agent that allowed salt to flow freely. Their popularity grew during the Great Depression when ceramics manufacturers began producing them inexpensively.
Prior to the popularity of salt and pepper shakers, diners used small plates or cups for dispensing salt and pepper, using small spoons or their fingers. Plates for holding salt and other spices were made from wood, pewter and animal horns during the Middle Ages. Silversmiths began crafting them from silver and gold during the 16th and 17th centuries and referred to them as “salts.” Containers and cups called spice boxes, dredging boxes and cellars became popular overseas during the 1850s but still allowed salt to form large clumps that had to be chipped or milled to sprinkle.