Most books in the Library of Congress are collected as materials. As it is the Library of Congress, domestic publications must submit samples of new books to it. There are less than one third of books in English and Chinese, and many rare books and local chronicles of China are also collected by it. In addition to books, there are 3.624 million ancient and modern world maps, atlases, globes, 33.39 million manuscripts (including those of 23 former American presidents), 6.5438+0.7 million laws, about 3.48 million microforms, about 3.67 million music materials, 6.5438+0.3 million scientific and technological reports, as well as pictures, printed matter and architectural sketches. In addition, there are a large number of periodicals, government publications and other serial publications. The museum also collects physical materials, such as violins made by Italian violinist Stella Qiuhuali and China Han bamboo slips. In addition to Congress, libraries also strive to meet the needs of various government agencies, scholars, writers and ordinary readers.