mansion was built in 1856 by
John Marsh. The
Mexican–American War began on May 13, 1846 with a
declaration of war by the
United States of America. Action in California began with the taking of
Monterey on July 7, 1846 (before knowledge of the declaration),
Los Angeles in August, other battles in December, 1846, then retaking of Los Angeles in January, 1847, which terminated the authority and jurisdiction of Mexican officials later that year. Armed resistance ended in California with the
Treaty of Cahuenga signed on January 13, 1847. The
Treaty of Guadalupe Hidalgo, ending the Mexican War, was signed February 2, 1848 and California became a Territory of the United States. Between 1847 and 1849, California was run by the U.S. military. A
constitutional convention met in Monterey in September 1849, and set up a state government. It operated for 10 months before California was admitted to the
Union as the 31st State by the
United States Congress, as part of the
Compromise of 1850, enacted on September 9, 1850.
Gold Rush While the end of the 1840s saw the close of Mexican control over Alta California, this period also marked the beginning of the rancheros' greatest prosperity. Cattle had been raised primarily for their hides and tallow, as there was no market for large quantities of beef, especially in the days prior to refrigeration, railroads or ice production. Demand dramatically changed with the onset of the
Gold Rush, as thousands of miners and other fortune seekers flooded into northern California. These newcomers needed meat, and cattle prices soared with demand. The rancheros enjoyed the halcyon days of Hispanic California.
Land claims , built by
Pío Pico in 1853 on
Rancho Paso de Bartolo was built on
Rancho Nipomo in 1839. The
Treaty of Guadalupe Hidalgo provided that the Mexican land grants would be honored. To investigate and confirm titles in California, American officials acquired the provincial records of the Spanish and Mexican governments in Monterey. The new state's leaders soon discovered that the Mexican government had given a number of grants just before the Americans gained control. The Mexican governors had rewarded faithful supporters, and hoped to prevent the new immigrants from gaining control of the land. Sponsored by California Senator
William M. Gwin, in 1851 Congress passed "An Act to Ascertain and Settle Private Land Claims in the State of California". Contrary to the Treaty of Guadalupe Hidalgo, this Act placed the burden of proof of title on landholders. Grantees were required to prove the validity of the grants they had received and establish their exact boundaries. The diseños (maps) available were often hand-drawn and imprecise. Land had until the gold rush been of little value and boundary locations were often quite vague, referring to an oak tree, a cow skull on a pile of rocks, a creek, and in some cases a mountain range. The settlement of land titles was frequently complicated and lengthy. Even in cases where the boundaries were more specific, many markers had been destroyed before accurate surveys could be made. Aside from indefinite survey lines, the Land Commission had to determine whether the grantees had fulfilled the requirements of the Mexican colonization laws. Mexican officials often did not keep adequate records and sometimes did not provide grantees with any documentation of the grant. Many grants required additional approvals before they were legal. Conditions of the grant required the grantee to live on the land. All of these requirements were rarely fulfilled. was built on
Rancho San Miguel in 1841. While the Land Commission confirmed 604 of the 813 claims it reviewed, most decisions were appealed to
US District Court and some to the
Supreme Court. The confirmation process required lawyers, translators, and surveyors, and took an average of 17 years (including the
Civil War, 1861–1865) to resolve. It proved expensive for landholders to defend their titles through the court system. In many cases, they had to sell or give title to a portion of their land to pay for defense fees or gave attorneys land in lieu of payment. Rejected Spanish and Mexican land claims resulted in conflicting claims by the grantees, squatters, and settlers seeking the same land. This resulted in pressure on Congress to change the rules. Under the
Preemption Act of 1841, squatters were able to
pre-empt others' claims to portions of the land and acquire clear title by paying $1.25 an acre for up to a maximum of . Land from titles rejected by the courts became part of the public domain and available to homesteaders after the first federal
Homestead Act of 1862 was passed, allowing anyone to claim up to . This resulted in additional pressure on Congress, and beginning with
Rancho Suscol in 1863, it passed special acts that allowed certain claimants to pre-empt their land without regard to acreage. By 1866 this privilege was extended to all owners of rejected claims. A number of ranchos remained in whole or in part in the sliver of territory of Alta California left to Mexico by the Treaty of Guadalupe Hidalgo, which then became part of
Baja California.
Rancho Tía Juana (partially in San Diego County, California) lost its claim to title to its land in San Diego County but the balance of the rancho was confirmed by the Mexican government in the 1880s.
Rancho El Rosario,
Rancho Cueros de Venado and
Rancho Tecate were each granted to citizens of San Diego in the 1820s or 1830s and lay wholly in what is now Baja California as was the
Rancho San Antonio Abad, whose origin and title is more obscure. Their titles were never subjected to dispute in U.S. courts. ==Disintegration==