Hazel-Atlas Glass Company
The Hazel-Atlas Glass Company was a large producer of machine-molded glass containers headquartered in Wheeling, West Virginia. It was founded in 1902 in Washington, Pennsylvania, as the merger of four companies: 
Hazel Glass and Metals Company (started in 1887)
Atlas Glass Company (started 1896)
Wheeling Metal Plant
Republic Glass Company

History
By the 1900s, Hazel-Atlas was a large glass maker, with 15 plants, including ones in Ada, Oklahoma; Clarksburg, West Virginia; Montgomery, Alabama; Oakland, California; Pomona, California and Zanesville, Ohio. Hazel-Atlas made large quantities of "Depression" pressed glassware in a wide variety of patterns in the 1920s–1940s, along with many white milkglass "inserts" used in zinc fruit-jar lids, many types of milkglass cold-cream jars and salve containers, and a large variety of bottles and jars for the commercial packaging industry. "Atlas" was the brand of the company's most popular line of fruit jars for home canning. Hazel-Atlas—then the third largest producer of glass containers in the United States, with almost ten percent of the market—became a subsidiary of the Continental Can Company in 1957. The acquisition was challenged under the Clayton Antitrust Act in a case that was eventually decided by the U.S. Supreme Court in United States v. Continental Can Co.. It continued to make containers, glassware, and tableware into the 1960s. In 1964, 10 of the 12 H-A plants in operation were sold to Brockway Glass Company, and it is unclear whether the remaining two plants used the H-A trademark after that year. Patterns

Hazel-Atlas produced dozens of different patterns, with unique names. The Hazel-Atlas mark, usually placed on the back of the product, is an "A" nestled underneath an "H". The mark was reportedly first used in 1923, according to trademark office records quoted by Peterson (400 Trademarks on Glass). External links and references 

Hazel-Atlas Depression glass a field unto itself, from a February 2005 article in The San Diego Union-Tribune
Hazel Atlas Glass Collecting Website
Summary of the Hazel-Atlas Glass Company, with discussion on types of glass made (webpage on the GlassBottleMarks.com site)

Defunct glassmaking companies
Glassmaking companies of the United States
Kitchenware brands
Companies based in Wheeling, West Virginia
Industrial buildings and structures on the National Register of Historic Places in West Virginia
Manufacturing companies established in 1902
1902 establishments in West Virginia
National Register of Historic Places in Marshall County, West Virginia
National Register of Historic Places in Wheeling, West Virginia
Defunct manufacturing companies based in West Virginia