When Norman Hapgood became editor of "Collier's" in 1903, he attracted many leading writers. In May 1906, he commissioned Jack London to cover the San Francisco earthquake, a report accompanied by 16 pages of pictures. Under Hapgood's guidance, "Collier's" began publishing the work of investigative journalists such as Samuel Hopkins Adams, Ray Stannard Baker, C.P. Connolly and Ida Tarbell. Hapgood's approach had great impact, resulting in such changes as the reform of the child labor laws, slum clearance and women's suffrage. In April 1905, an article by Upton Sinclair, "Is Chicago Meat Clean?", persuaded the Senate to pass the 1906 Meat Inspection Act.