Final answer:
The Supreme Court case combining cases from families across multiple states that led to desegregation of schools is known as Brown v. The Board of Education of Topeka, Kansas. The decision held that separate schools for different races violated the equal protection clause of the Fourteenth Amendment.
Step-by-step explanation:
The landmark Supreme Court case that combined the court cases of 12 different families is known as Brown v. The Board of Education of Topeka, Kansas. This case was a significant legal and educational milestone because the Supreme Court ruled that separate schools were inherently unequal and therefore violated the equal protection clause of the Fourteenth Amendment.
This ruling ultimately led to the desegregation of schools across the United States. The Brown v. Board of Education decision also reflected a broader trend in the judiciary where court interpretations evolve with changing times and societal norms, as demonstrated by previous and subsequent landmark Supreme Court cases. These cases have collectively expanded the rights of individuals and underscore the principle of 'Equal Justice Under Law.'