Final answer:
Progressive reform under President Theodore Roosevelt was transformative, as he pushed an agenda focused on corporate regulation, consumer protection, and conservation, resulting in significant legislation and establishing a stronger federal role in economic affairs.
Step-by-step explanation:
Progressive reform during Theodore Roosevelt's presidency can best be described as robust and transformative. Known for his dynamic personality and vigorous lifestyle, Roosevelt used his presidency as a "bully pulpit" to promote his Progressive agenda, emphasizing the three C's: control over corporations, consumer protection, and conservation. He pushed through significant legislation like the Elkins Act to prevent unfair business practices and endorsed a variety of Progressive policies ranging from women’s suffrage to federal welfare programs while campaigning. Despite starting cautiously, his tenure was marked by an expansion of federal power and the laying of groundwork for later reforms under his successors.