关于杨鹏长难句的问题，就一句，请大神抽空指导啊！

lisney

这个句子最后的its怎样看出是指的不是W的而是NAACP的呢？？什么思路呢？？
This revisionist view of Jim Crowlegislation grew in part of the research that Woodward had done for the NAACPlegal campaign during its preparation for Brown v. Broad of Education.