The Porfiriato period (1876–80 and 1884– 1911, when Mexico was ruled by the dictatorial president Porfirio Díaz) was a time of great economic and social strain on Mexican nationals who were attempting to make a living in the rural communities of Mexico. Land was mostly owned by large companies and investors in a hacienda fashion, which meant that many poor Mexican farmers found themselves subject to share cropping, often at a cost that far exceeded their income and made survivability nearly impossible and social mobility absolutely unheard of. Meanwhile, in the United States, the expansion westward and subsequent closing of the frontier by the railroads meant that there were numerous opportunities for jobs that required little to no training, such as working on the rail lines or harvesting crops.