Designed to support the Canadian policy of preferring agriculturalists to all other immigrants, this measure made it illegal to contract and import foreign laborers. The act was a response principally to the highly organized and rapid influx of Italian, Polish, Ukrainian, Russian, and Bulgarian laborers in the late 19th century. Although labor unions bitterly complained that the measures were routinely flouted, the government took no effective steps to enforce the act beyond applying more rigorous medical tests to Japanese immigrants from Hawaii. Although Minister of the Interior Clifford Sifton preferred agriculturalists seeking homesteading funds over contract laborers, the Canadian government generally deferred to industry’s need for additional laborers. In 1900, the measure was amended to prohibit advertisement for laborers in U.S. newspapers and to prohibit entry of non-American workers by way of the United States. Provisions of the measure were applied selectively after the Vancouver Riot of 1907 in order to keep Japanese and Chinese laborers from entering from Hawaii. In order to further limit the influence of labor unions and to allow U.S. laborers to relieve labor shortages in Canada, the government suspended the Alien Labor Act in 1916.