How to Identify USA Marked & Numbered Pottery

As antiques pass through time, they change hands and develop history. A family heirloom comes with a story of all the places it has been. Pottery you fall in love with as it sits on a shelf in an antique store has a story, too. Learn part of this story by identifying the piece's origin, maker, rarity and value. Read beyond a "USA" mark on the bottom of a planter or bowl; it tells only that the piece was made in the United States. Learn about the characteristics of American pottery so you can identify its origin and uncover something about its history.

Learn what the identifying marks, weight, color, glaze and foot can tell you about the origin of marked and numbered pottery. Check your local library for books on collecting and the history of American pottery, including "Art Pottery of America" by Lucile Henzke and "American Art Pottery: Identification & Values" by Dick Sigafoose.

Pick up a piece of pottery and turn it over. A piece marked with a company name or identifiable logo tells you clearly the manufacturer of the pottery. Numbers molded into the bottom of American pottery pieces identify molds, shapes and even product lines. Some companies used two numbers, some used four. Numbers alone do not necessarily identify the maker, but they can help.

Look for a "USA" mark and a number on the bottom. The "USA" stamp identifies the piece as American made, although it could have been produced by any one of many American pottery companies. The most prolific users of the "USA" mark were Shawnee and McCoy.

Identify the true unfinished color of the piece by examining any unglazed areas on the bottom. Certain clay colors, used in conjunction with specific styles of pottery, help narrow the maker and location. For example, yellow clay came from Ohio; most of the Ohio potteries, including Roseville, McCoy and Brush, used yellow clay .

Examine the surface of the base bottom where "USA" is stamped. This area may include legs, a bottom rim, dry wedges or rectangles, or a flat underside that is glazed or unglazed. These characteristics help tie the piece to a specific maker.

Note any small holes on the bottom of the pottery; these were created by stilts or firing pins. Identifying these characteristics further helps tie the piece to a specific maker. For example, if you find a piece with a bottom that is glazed over completely and includes three small marks for stilts, you may be holding a Haeger or Royal Haeger piece.

Study the glaze on the pottery. Pottery pieces marked "USA" were produced with both matte--that is, dull--and shiny finishes. Different finishes were used during different eras of pottery production, depending on the manufacturer. Pieces from the early 20th century show a shiny standard glaze. By 1915, matte finishes were in style. Many American pottery manufacturers returned to a shiny glaze finish from the late 1930s through the 1960s, although this varies from manufacturer to manufacturer. Collectors favor matte glaze pieces, so these usually sell for higher prices.

Gather all your observations. Check them against authoritative reference sources to see if you can positively identify the manufacturer, year of production, style name and other details of your piece of pottery.

Take your pottery to an expert appraiser if you're uncertain your identification is correct. In addition, the seller of the piece that interests you may be able to help you identify the manufacturer. Ask plenty of questions so you can make an educated decision whether or not you want to make the purchase.