Q: Do you have any idea what these cans are and what they’re worth? They are metal and a little thinner than license plates. They bend easily and each is marked with the name of a state and the year the state entered the union. In the upper left corner of the back of one of the cans, there are numbers next to the word “Gauge.”

A: Soft drinks were first sold in aluminum cans in 1964. The cans are made from flat sheets of an aluminum alloy that contains small percentages of manganese and magnesium. After the design is printed on the sheets, they are cut and formed into cans. You have the cut sheets for the 7Up cans that made up the Bicentennial commemorative set, which was issued in 1976. After the end of that promotion, the unused cut sheets were sold. The cans are numbered 1 through 50 for the 50 states. Instructions on the first can tell how to stack the cans so that the backs, the part with the blue letters with the name “7UP” repeated over and over, form a picture of Uncle Sam. The 50th can has the words “United We Stand” written on it. 7Up was introduced in 1929 by the Howdy Corp. of St. Louis. 7Up was originally called “Bib-Label Lithiated Lemon-Lime Soda” and was advertised as having “seven natural flavors blended into a savory, flavory drink with a real wallop.” Later the name of the drink was changed to 7Up Lithiated Lemon Soda, and in 1936 the name became just 7Up. The original drink contained lithium, which is used today as a mood-stabilizing drug. Lithium was removed in the 1940s. The formula for 7Up has been changed several times, most recently in 2010. In 1936 the company name became Seven-Up Co. It is now part of the Dr Pepper Snapple Group, which is owned by Cadbury Beverages North America.