William Dudley "Big Bill" Haywood (February 4, 1869 – May 18, 1928), was a founding member and leader of the Industrial Workers of the World (IWW), and a member of the Executive Committee of the Socialist Party of America. He was involved in several important labor battles throughout the United States at the beginning of the 20th Century. Haywood was an advocate of industrial unionism, a labor philosophy that favors organizing all workers in an industry under one union, regardless of the specific trade or skill level. He was also advocated multi-ethnic unions.