Contra Costa County, California
In 1821 Mexico gained independence from Spain. While little changed in ranchero life, the Mexican War of Independence resulted in the secularization of the missions with the re-distribution of their lands, and a new system of land grants under the Mexican Federal Law of 1824. Mission lands extended throughout the Bay Area, including portions of Contra Costa County. Between 1836 and 1846, during the era when California was a province of independent Mexico, the following 15 land grants were made in Contra Costa County.
History of North America
Meanwhile, Spain's hold on Mexico was weakening. Independence was declared in 1810 by Miguel Hidalgo, starting the "Mexican War of Independence". In 1813, José María Morelos and the Congress of Anáhuac signed the Solemn Act of the Declaration of Independence of Northern America, the first legal document where the separation of the New Spain with respect to Spain is proclaimed. Spain finally recognized Mexico's independence in 1821.