The Magnuson Act, also known as the Chinese Exclusion Repeal Act of 1943, was immigration legislation proposed by U.S. Representative (later Senator) Warren G. Magnuson of Washington and signed into law on December 17, 1943 in the United States.t allowed Chinese immigration for the first time since the Chinese Exclusion Act of 1882, and permitted some Chinese immigrants already residing in the country to become naturalized citizens. This marked the first time since the Naturalization Act of 1790 that any Asians were permitted to be naturalized.