Where were the key contributions of Theodore Roosevelt as the US President?

Answer 1

Trust Busting--He was instrumental in breaking apart numerous "trusts" (companies or entire industries that used collusive business models). He also helped to create the FDA (Food and Drug Administration) to oversee the safety of those products. For these actions he was known as a "Progressive" in American politics.

National Parks--He started (or at least greatly enhanced) the National Park system of the United States, placing millions of square acres off limits to development. For this he is sometimes thought of as the first "Environmentalist President".

The Great White Fleet--He sent the U.S. Navy on a "round the globe" venture in an effort to announce the presence of the United States on the political and military world stage. In a sense, he launched the U.S. as an imperial power. His "diplomatic" motto was "Talk softly and carry a big stick"...which became known as "Big Stick Diplomacy".

Man of Peace--He negotiated the peace treaty leading to the end of the Russo-Japanese War on 1905 (and won the Nobel Peace Prize for his efforts).

Answer 2

Good answer, epublius76. But you can't forget about the Panama Canal.