Chicano literature is the literature written by Mexican Americans in the United States. Although its origins can be traced back to the sixteenth century, the bulk of Chicano literature dates from after 1848, when the United States annexed large parts of what had been Mexico in the wake of the Mexican-American War. Today, it is a vibrant and diverse set of narratives, prompting (in the words of critics) "a new awareness of the historical and cultural independence of both northern and southern American hemispheres."
The definition of Chicano/Mexican American literature is not set in stone, as the term could conceivably encompass both Mexicans who have moved to the United States and US-born people of Mexican ancestry; this latter group includes many Spanish-speaking families who have been in the United States for generations, often living on the land (e.g., in Texas, New Mexico, Arizona and California) before it was part of the United States, and have often faced a different set of issues than their Mexican neighbors because of their status as a linguistic and cultural minority, that is, because they are Spanish-speaking Catholics in a predominantly English-speaking Protestant country. Thus, people from Southern Texas have historically had different issues than people in Northern Mexico (who themselves have different issues than those coming from Southern Mexico, etc.). We might also wonder whether the term applies to American families who have assimilated to US culture.
Other issues arise when we try to add race into the mix, as some Mexicans are of mostly Spanish heritage, whereas many others come from the intermixture of Spanish and indigenous peoples: how different are the perspectives of the mestizo Mexican population from those of the Hispano population? Further, there is the issue of people from Mexico who are neither of Spanish nor Mexican stock, such as Josefina Niggli, whose parents were Euro-Americans living in Mexico when she was born; although she is considered Anglo in the broader ethnic sense of the term, she felt more connected to Mexican culture and wrote most of her novels and plays around Mexican themes.
Chicano or Mexican American writing includes those works in which a writer's sense of ethnic identity (chicanismo) animates his or her work manifestly and fundamentally, often through the presentation of Chicano characters, cultural situations, and patterns of speech.