During which years did Roosevelt serve as President, marked by significant Progressive reforms?

Roosevelt served as President from 1901 to 1909, a period characterized by significant Progressive reforms. He initially took office after the assassination of William McKinley in September 1901 and was subsequently elected to a full term in 1904, serving until March 1909. During his presidency, he implemented a variety of reforms aimed at curbing corporate power and increasing government intervention in the economy, which were central themes of the Progressive movement, including trust-busting, consumer protection, and conservation efforts.

This timeframe is essential to understanding Roosevelt's impact on American politics and society, as he championed progressive ideals and established a more active role for the federal government in regulating the economy for public welfare.