Recognizing the challenge of cultivating marginal arid land, the United States government expanded on the 160 acres offered under the Homestead Act—granting 640 acres to homesteaders in western Nebraska under the Kinkaid Act (1904) and 320 elsewhere in the Great Plains under the Enlarged Homestead Act (1909). Waves of European settlers arrived in the plains at the beginning of the 20th century. A return of unusually wet weather seemingly confirmed a previously held opinion that the "formerly" semiarid area could support large-scale agriculture, which was readily enabled by technological improvements such as mechanized plowing and mechanized harvesting