Costco's history began with Sol Price and his son, Robert, opening the first Price Club warehouse on July 12, 1976, on Morena Boulevard in San Diego, California, thus giving birth to a new concept: a retail warehouse club. The Price family placed Price Club Warehouse #1 inside a series of old airplane hangars previously owned by Howard Hughes; that warehouse, now known as Costco Warehouse #401, is still in operation today.

Costco opened its first warehouse in 1983 in Seattle on September 15, by James (Jim) Sinegal and Jeffrey H. Brotman. Sinegal had started in wholesale distribution by working for Sol Price at FedMart; Brotman, an attorney from an old Seattle retailing family, had also been involved in retail distribution from an early age. He began his retail involvement as a grocery bagger. A second store opened in Portland in October, and a third in Spokane in December 1983. In 1997, Costco changed its name to Costco Wholesale Corporation, and all remaining Price Club locations were rebranded as Costco

A typical Costco warehouse carries only 3,700 distinct products, while a typical Walmart Supercenter carries approximately 140,000 products. If Costco feels the wholesale price of any individual product is too high, they will refuse to stock the product. The company's rule is that no item may be marked up more than 14% over cost and no Kirkland Signature item may be marked up more than 15% over cost. The company runs very leanly, with overhead costs at about 10% of revenue and profit margins at 2%.

Costco has a frequently changing inventory and is known for carrying products for a time, then discontinuing them or using them as seasonal products. Over the years, Costco has gradually expanded its range of products and services.

Costco was the first company to grow from zero to $3 billion in sales in under six years. For the fiscal year ending on August 31, 2012, the company's sales totaled $97.062 billion, with 2.709 billion net profit. As of 2019, Costco is ranked #14 on the Fortune 500 rankings of the largest United States corporations by total revenue.

According to en.wikipedia