Final answer:
In 1941, Roosevelt began an unprecedented expansion of governmental power through his implementation of the New Deal policies.
Step-by-step explanation:
He implemented a series of policies known as the New Deal, which aimed to stimulate the economy, provide relief to the unemployed, and enact social reform.
He also began an unprecedented expansion of governmental power, particularly in response to the economic crisis of the Great Depression and the demands of World War II.
Examples of Roosevelt's unprecedented actions include his use of executive orders to bypass Congress, the establishment of government agencies like the Works Progress Administration and the Social Security Administration, and the implementation of financial regulations such as the Securities Exchange Act.
These measures marked a significant shift in the role of the federal government in guiding the economy and providing direct assistance to the people.