Under the Treaty of Guadalupe Hidalgo in 1848, which formally ended the Mexican-American War, the United States assumed control over vast new territories, including much of what is now the state of New Mexico. The United States agreed to recognize ownership of property, including the ownership of land grants, in the ceded areas. Whether the United States carried out the provisions of the treaty, especially with regard to community land grants, has been a controversial issue for generations. Land grant documents contained no direct reference to \“community land grants,\” nor do Spanish and Mexican laws define or use this term. GAO did find, however, that some grants refer to lands set aside for general communal use or for specific purposes, such as hunting, maintaining pastures, wood gathering, or watering. Scholars, the land grant literature, and popular terminology commonly use the phrase \“community land grants\” to denote land grants that set aside common lands for the use of the entire community. GAO used this broad definition to determine which Spanish and Mexican land grants could be identified as community land grants. GAO identified 152 community land grants out of 295 land grants in New Mexico. GAO divided these community land grants into three distinct types: 79 of these were grants in which the shared lands formed part of the grant according to the original grant documentation; 51 were grants that scholars, grantee heirs, or others believed to contain common lands; and 22 were grants extended to the indigenous pueblo cultures in New Mexico.