I believe it was the attack on Pearl Harbor
Answer:
The Chinese and the Mexican-Americans were the bulk of workers who built the American transcontinental rairoad in the 19th century. The Chinese arrived in large numbers in the second half of the century escaping poverty and turmoil in China, and there were large Mexican populations living in the USA. Only agricultural work offered more employment to Mexicans than the railroad works.
Explanation:
The only state that did not go was Rhode island so I'm guessing A.
