Read the paragraph. Horace Mann was a reformer who helped bring about public education in the United States during the 1800s. After practicing law and serving in the state legislature, he became secretary of the Massachusetts State Board of Education. He gave speeches that helped define public schools as schools paid for by taxes. Mann pushed for laws that required children to attend school. In 1839, he helped established the first teacher-training school. He briefly served in the US Congress and then became president of Antioch College in Ohio.

Based on the information you were just given, which broad idea could best be used to organize an essay about Horace Mann’s influence?