During his presidency, Roosevelt initiated the construction of the Panama Canal, increased regulation against big business, improved national forest and sanctuary programs, and passed the Food and Drug Act. In his 1904 re-election campaign, Roosevelt won by the largest popular vote majority ever received by any presidential candidate.

In November 1902, Roosvelt attended a bear hunt in Mississippi, where a bear was tracked, clubbed, and tied up. He was apalled at the treatment of the bear, and refused to allow anyone to claim it. A cartoon of this story became wildly popular, and "Teddy's bear" became a longlasting nationwide legend.

Theodore Roosevelt became the first American President to be awarded the Nobel Peace Prize.