How do you know where an old pop bottle was manufactured?

Older soda bottles made of glass often have manufacturing marks that indicate the company, site and potentially date of manufacture of the bottle. These marks often include a specific trademark symbol associated with the manufacturer along with other information in a coded form, but specifics vary from bottle to bottle.

The trademark symbols used on old soda bottles can sometimes be used to roughly date a bottle even if no other information is available. Many manufacturers have changed these symbols over time or were only involved in manufacturing bottles for a specific soda during a certain time range. For example, the Owens-Illinois glass company used an O inside a diamond on Coca-Cola bottles manufactured before the mid-1950s, but switched to an I inside a circle after that time.