Rapid Growth of Industry
Fruit and vegetables processing plants sprang up in Ohio, Indiana, Illinois, and California. Pacific salmon was first canned on the Sacramento River in 1864 and on the Columbia River in 1866. In 1874, A. K. Shriver of Baltimore invented the pressure cooker which enabled canners to control temperatures accurately while cooking sealed cans—preventing them from exploding. The number of processing plants grew from less than one hundred in 1870 to nearly eighteen hundred at the turn of the century.
Norton Brothers merged with 60 other firms, with 123 factories, to form the American Can Company in 1901. Edwin Norton became president of the new conglomerate and kept his headquarters at the original Norton plant in Illinois. Forbes magazine would, in 1941, call American Can a corporation that "shaped the daily lives of man in the United States." In 1904, Norton left American Can to form the Continental Can Company. That same year, the Sanitary Can Company was formed from three New York can companies and began production of the sanitary—or open top—can which, since the lid was crimped on after filling, required no soldering. By the 1920's, the hole and cap model can was history. Meanwhile, can manufacturing became its own niche. The Norton Brothers Company of Chicago, for example, specialized in producing vegetable cans. In 1883, this company invented the semi-automatic body maker, which mechanically soldered seams on the side of the cans and increased production capacity to 2,500 cans per hour; a decade later it would reach 6,000 an hour.
As production increased, so did the number of things you could purchase in cans. The investment canners had made in their production lines required that they find new foods to can and keep their businesses running year round. Campbell's condensed soups were introduced nationally in 1899 and sold for a dime. The red and white labels were inspired by Cornell University's football jerseys and the gold medallion at center represented a gold medal the soup won at the 1900 World's Fair in Paris. Tuna fish was first canned in 1909 when one processor ran out of the sardines he usually canned. By then, 63 different kinds of meat were available in cans. Citrus fruits and tomato juice first appeared in cans around 1920.
Industry's inventions brought greater success, new capabilities, and more competition to the canning market. The railroad transferred goods across the country. A new type of labor force emerged to work the production lines. Conveyor belts and automatic machinery such as washers and fillers moved the products through at astonishing rates. Still more machines shucked corn and peas, trimmed kernels off corncobs, pitted cherries, even peeled and sliced fruit. Factories hummed and Americans bought more and more quantities and varieties of canned goods. The onset of winter previously had meant that households had to put up provisions—dried meats and fruits, potatoes stored in root cellars, and vegetables canned at home. Now an endless variety of foods were available year round. Some were so exotic and foreign that they were being tried by American consumers for the first time.
The earliest cans were laboriously made by hand. Iron was pounded into sheets and dipped into molten tin. The resulting tinplate was then soaked in brine baths, creating a hot and odorous atmosphere. Using considerable skill and muscle, artisans cut the sheets into rectangular bodies and round ends. The body pieces were bent around a cylindrical mold and the seams and ends were soldered in place. One of the ends was made with a circular hole through which the food would be stuffed. Once filled, the holes were plugged with a soldered metal cap. This soldering process sometimes left a bit of soot mixed in with the can's contents.
This process allowed even the most skilled workers to only make about ten cans per day. Eventually mechanization and the invention of the "sanitary can" sped these processes. The "sanitary can" folds the edges of the can and ends over twice, forming a strong seal. This method eliminated the need for the hole and cap method of filling as well as the residual soot from soldering. Mechanical body makers, industrial die cutting, and machine-pressed tinplate all improved can making during the early part of the century.
Today there are more than 600 sizes and styles of cans being manufactured. The amount and combination of tin and steel used to form the tinplate varies as well, depending upon the function of the can. The tin coating is usually as thin as a human hair, but still serves to protect the can inside and out against rusting. Protective coatings applied to the inside of the cans also ensure the integrity of the contents and have allowed cans to hold many products, such as citrus fruits, which would otherwise be too corrosive. Tin-free steel and aluminum have added even more flexibility and versatility to the modern day can line.