Franklin Roosevelt uttered this famous remark in his first inaugural address, which was given at the lowest depths of the Great Depression, in 1933. While it could certainly have been applied to the events of the late 30s and especially the World War II era, it is best understood in the context of the time the address was given. By 1933, the Depression had wrecked the economy, putting millions of Americans out of work, and in fact the nation was experiencing yet another in a series of bank panics (caused, not coincidentally, essentially by investor fears)at the time of the inauguration. The famous line in many ways was thus a rallying call for the American people.
But it was also, as historian David Kennedy has argued, the basis of the policies that Roosevelt enacted, especially as part of the Second New Deal. FDR and his advisors implemented a number of programs aimed at recovery and relief, but the lasting legacy of his reforms would be the idea that the government had a role to play in providing economic security for individuals and for the capitalist system in general.