Launched in 1974, the Darwin Correspondence Project centers on an impressive collection of 8,500 transcribed letters authored by or addressed to Charles Darwin. In recent years, this longstanding project has added to its impressive collection of correspondence and introduced a number of new features, including lesson plans, multimedia resources, short essays, and more. The letters collection can be explored in a few ways, including via an extensive timeline within The Letters section. Here, letters are organized by date and accompanied by a short description; when visitors select a letter, they may also view letters involving the correspondent. These letters include personal correspondence with family along with letters from other naturalists, biologists, and geologists that helped Darwin craft his theories. Visitors can learn more about these correspondents via the People tab; visitors may also be interested in a short essay, "Correspondence with Women," available via the Letters tab. Meanwhile, educators will find a variety of teaching resources organized by level (from Kindergarten through University) in the Learning Resources section.