Levi Strauss & Co. is an American clothing company known worldwide for its Levi's brand of denim jeans. It was founded in May 1853 when German immigrant Levi Strauss moved from Buttenheim, Bavaria, to San Francisco, California, to open a west coast branch of his brothers' New York dry goods business. Although the corporation is registered in Delaware, the company's corporate headquarters is located in Levi's Plaza in San Francisco. All jeans and pants are categorized by fit—skinny, slim, straight, bootcut, taper, relaxed, flare, and "big & tall"—identified by trademarked three-digit numbers. The 501, the company's original modern design, is available in styles for both men and women. The rest of the 500 series is designed for men, and the 300, 400, 700, and 800 series are designed for women.