1848 gold was discovered by James W. Marshall at Sutter's Mill, in Coloma, California. News of the discovery soon spread, resulting in some 300,000 men, women, and children coming to California from the rest of the United States and abroad. These early gold-seekers, called "forty-niners," traveled to California by sailing boat and in covered wagons across the continent, often facing substantial hardships on the trip. San Francisco grew from a small settlement to a boomtown, and roads, churches, schools and other towns were built throughout California. A system of laws and a government were created, leading to the admission of California as a state in 1850 Site of the opening engagement of the Civil War. On December 20, 1860, South Carolina had seceded from the Union, and had demanded that all federal property in the state be surrendered to state authorities. Major Robert Anderson concentrated his units at Fort Sumter, and, when Lincoln took office on March 4, 1861, Sumter was one of only two forts in the South still under Union control. Learning that Lincoln planned to send supplies to reinforce the fort, on April 11, 1861, Confederate General Beauregard demanded Anderson's surrender, which was refused. On April 12, 1861, the Confederate Army began bombarding the fort, which surrendered on April 14, 1861. Congress declared war on the Confederacy the next day. In the latter years of the 1800s, southern states implemented a system where they leased black convicts from their prisons to businesses and planters to build railroads, clear swamps, work mines, cut timber, and tend cotton. Companies and planters had to feed, clothe, and house the prisoners, but prisoners were treated harshly, shackled, beaten, overworked, and underfed. They provided cheap labor while southern states received large revenues without maintaining prisons. Law enforcement officials were encouraged to arrest black men with assorted menial crimes to increase this labor force and state revenue.