The shot glass, as we know it today, has gone through an interesting evolution throughout human history, influenced by many cultures including those in Africa, China and Europe.1800's to date
One Definition of a Shot Glass History of Glass Rule"
For all intents and purposes, shot glasses may be defined as "whiskey tumblers which are small vessels made of glass designed for drinking distilled spirits in small amounts." The sizes may vary slightly, but as a rule shot glasses should be no shorter than 1-3/4 in. and no taller than 3 in.; consequently, the volume ranges from one to two ounces as dictated by the height.

"Real" shot glasses don't have stems (like champagne or wine glasses) or handles (like mugs or steins) or feet (like pilsners or snifters glasses). They are made of glass, not metal or plastic. Shot glasses usually taper outwards, the diameter being greatest at the top of the glass, but there are exceptions. Some have no taper at all, while others have a base diameter greater than the top. Traditional tumblers are round. There are some square shot glasses, 2-1/2 in. tall, that hold 2 ounces.

The history of the standard shot glass began about 100 years ago and today many variations of the shot glass are common. Collectors find glass, metal, plastic, ceramic and other materials being used for a endless variety of styles and colors. The taller glasses like some of the tall Hard Rock Cafe glasses, are technically not shot glasses and are usually referred to as "shooters."

A shot glass is a small glass designed to hold or measure liquor, to be either poured into a mixed drink or drunk straight from the glass (a "shot").

Jigger or pony is an earlier name for a container used to measure or drink a standard quantity of liquor. A small glass holding a shot of liquor is called a whiskey. American distilleries distributed thin whiskey glasses bearing etched advertising between the late 19th century and the beginning of Prohibition. Shot glasses decorated with a wide variety of advertising, humorous pictures, and toasts are popular souvenirs and collectibles. Care must be taken when drinking from decorative shot glasses, as some decorations (such as coloring or pictures) contain lead. Pre-prohibition whiskey glasses are also highly collectible.In Italy, the shot glass has been used for over 200 years, very popular in taverns for tasting grappa. Grappa is sipped from the shot glass, not downed in one gulp.