Final answer:
The Progressive Era reforms of initiative, referendum, and recall significantly increased citizen participation in governance and strengthened direct democracy, giving citizens more direct control over legislation and public officials.
Step-by-step explanation:
The most important effect of the Progressive Era reforms of initiative, referendum, and recall has been to increase citizen participation in the electoral process and thereby strengthen forms of direct democracy. These reforms have allowed citizens greater power in the legislative process by enabling them to propose legislation (initiative), approve or reject laws passed by the legislature (referendum), and remove public officials from office (recall). The introduction of these processes has served to reduce the influence of special interests, facilitate the passage of laws like anti-child labor legislation, and more directly connect people with their government, thereby ensuring that it better reflects the will of the populace.