Zinc, or "White Bronze" headstones and markers can be found throughout North America. Headstones are the most common use for these markers. There are also a few war memorials, mainly Civil War, made of Zinc that are acceptable in this category. They are rare in that they were only produced from the mid 1870's through 1912, and only by one company. All of these markers were produced by a company founded in Bridgeport, Connecticut. In 1881 Bridgeport set up its first subsidiary, in Detroit. Later, it also opened plants in Philadelphia, New Orleans, St. Thomas, Ontario, Des Moines and Chicago.
They are made of cast zinc, which allowed them to be produced and shipped around the world less expensively, as compared to more traditional stone monuments. Unfortunately this was also their downfall. Many people felt that because they were so inexpensive, that it would not be proper to remember their loved ones with such a monument. The headstones eventually gained the euphemism "White Bronze," in place of “zinc,” by sales people who wanted to make them seem more attractive to the public.
In purchasing one of these, a person would select a general monument type and style. They then could customize all of the four sides of the monument, if they wished, with a plate which was screwed to the headstone using decorative screws. The plates typically list the name of the deceased, along with date of birth, date of death, and relationships to others who may be buried in the same plot.
A few examples of what you're looking for