It is to be noted that California apologized in 2005 for forcibly relocating Mexican-Americans in the 1930s. The gap in time between when the time the law was passed and the events it discussed suggest that the event is historically accurate.
What is the meaning of this?
So, imagine you found out that something really unfair happened to your grandparents whenthey were young.
Now, think about if the government officially said sorry for that unfair thing many years later.
That's kind of what happened here. The California government apologized in 2005 for a program in the 1930s that forcefully moveda lot of Mexican people, even if they were U.S. citizens.
Because so much time had passed, it shows that they've really thought about it and realized it was wrong and that the event is historically correct.
Full Question:
Although part of your question is missing, you might be referring to this full question:
Apology Act for the 1930s Mexican Repatriation Program
How might the gap in time between when this law was passed and the events it discusses make it a more reliable source of information about Mexican immigration in the 1930s?