Immigration to Oregon surged after 1840. The first white settlers to the area arrived in 1836. In 1843 a territorial government was established, with provisions for land ownership. A system of donation land claims was established and a married man was entitled to 640 acres of land. Most of the claims were in the Willamette Valley. Immigration increased in the late 1840s when many people left the Mississippi River valley because of the many diseases being spread: malaria, measles, smallpox, and tuberculosis. Population increased from 12,000 in 1850 to 318,000 in 1890. The settlers brought a variety of seeds and livestock--even bees--but many were diverted to California following the discovery of gold. Gold also was discovered in southwestern Oregon in 1850 and in eastern Oregon in 1860. Oregon became a state in 1859. In the 1870s the railroad aided timber and other industry and enabled fruit grown in Oregon to be marketed in the East.