Final answer:
The exception for the segregation of the first grade in the 1947 Texas desegregation order was rationalized based on language skills, as it was claimed that Mexican American children needed additional English language support.
Step-by-step explanation:
In the 1947 Texas desegregation order, there was an exception that allowed the first grade to continue to be segregated. The rationale for this exception was based on the claim of language skills. School officials argued that Mexican American children often required additional assistance with English before integrating with other students. This exception persisted despite the fact that non-English speaking children of European descent were typically permitted to attend schools of their choice. The segregation practices for Mexican American children were largely due to cultural and linguistic biases, rather than legal mandates, as the laws at the time were silent or ambiguous regarding the segregation of these minority groups.