Complex sentence: At the time, half of public school students were of Japanese ancestry and the White minority and began petition Governor Charles J. McCarthy for racial segregation to prevent their children for being exposed to corrupting influences of the colored students.
Split into simpler sentences: At the time, half of public school students were of Japanese ancestry. The white minority petitioned Governor Charles J. McCarthy for racial segregation to prevent their children for being exposed to corrupting influences of the colored students.