Chartered by Congress in 1920, the Theodore Roosevelt Association (TRA) preserves and perpetuates T.R.'s memory. His own children were heavily involved in its organization and founding. Their website, although short on presentation, offers lots of useful information, including essays exploring Roosevelt's legacy, on-line access to the Theodore Roosevelt Encyclopedia, and links to other T.R. resources.
Another resource-heavy but presentation-poor website. Be careful: unlike the other sites on this list, this website is someone's personal hobby, and not an institutional product. It is not maintained or verified by a university or a scholarly association. Still, the sheer volume of material it collects—speeches, essays, books, photographs, cartoons, and all sorts T.R. memorabilia—makes it worth a look.
This website complements the PBS American Experience episode on Theodore Roosevelt. It includes helpful timelines, analyses of different aspects of Roosevelt's presidency, and access to selected primary sources, including the platform of the Bull Moose Party.
The Miller Center of Public Affairs at the University of Virginia offers a snapshot of T.R.'s presidency through short biographies of his administration and links to his speeches and papers. Also includes research guides for further study.
Theodore Roosevelt was the first president to of age in the era of visual and audio recording. This website makes the Library of Congress's extensive recording of T.R. available online. It also includes helpful timelines and analytical essays discussing T.R.'s relationship to recording technology.
As this exhibit of the National Portrait Gallery shows, it's difficult to overestimate just how much of an icon T.R. was. Put together by the Smithsonian Institution, this stunning website explores Theodore Roosevelt as an image. It includes photographs, paintings and drawings of T.R. and related subjects. Intelligent commentary places the images in context.