Only if you don’t have passports, passport cards or enhanced driver’s licenses.
Americans entering Mexico by land, sea or air must present photo identification and proof of citizenship. Passports, passport cards or enhanced driver’s licenses are one way. These documents are government issued and certify a person’s claim of citizenship and identity. An easier method for individuals over age 16 is presenting a government-issued photo identification card (a driver’s license, military identification card or state-issued non-driver’s identification card) and proof of citizenship (certified birth certificate, Naturalization Certificate, Consular Report of Birth Abroad, Certificate of Citizenship). Children need only proof of citizenship to cross the border.