Editor's note: Tomás R. Jiménez is an assistant professor of sociology at Stanford University and an Irvine Fellow at the New America Foundation. He is also author of the forthcoming book, "Replenished Ethnicity: Mexican Americans, Immigration, and Identity" (University of California Press). Tomás Jiménez says many Mexican-Americans are the children of U.S.-born parents. (CNN) -- Just about any celebration of Hispanic Heritage Month (September 15 - October 15) will highlight the diversity among Hispanics. They come from different parts of the Spanish-speaking world, have settled in various areas of the United States, have distinctive customs and come in all shapes and colors.
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Tomás Jiménez: Mexican-Americans often perceived only as immigrants
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He says nearly a third were born in the U.S. to parents also born in the U.S.
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He says assumptions about Mexican-Americans being foreign can be scary
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Jiménez: Mexican-Americans have a rich heritage to celebrate
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Hispanics are not just immigrants or the @placeholder-born children of immigrants.
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They are also @placeholder with deep family histories in the United States.
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Ask the later-generation descendants of earlier waves of @placeholder immigrants, and they'll tell you that "Where are you from ... no, where are you really from?"
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And even if it's clear that they are Mexican-Americans, they still get quizzed about how well they speak @placeholder.
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Corporations, retailers, political parties and churches are all trying to grab a slice of the "Hispanic market," the overwhelming majority of which is @placeholder.
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All of this attention adds cachet to @placeholder ancestry that even later-generation individuals enjoy.
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@placeholder, in contrast, don't have to worry about ethnic blandness because the opportunities to celebrate their heritage are all around.
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No matter how deep or shallow their roots extend into American history, what almost all @placeholder have in common is that immigration profoundly defines their experience.