225 years ago today, on April 24, 1800 (April 1, 1800, lunar calendar), the Library of Congress was established. On April 24, 1800, as the U.S. government moved from Philadelphia to Washington, then the second president, John Adams, approved the purchase of books worth $5000 (a huge expense by the time) to meet congressmen's needs. The Library of Congress was thus established. Later, there were two fires in 1814 and 1851, burning two-thirds of the precious books in the collection. From 1870 to 1980, as the collection of books continued to increase, the Library of Congress underwent three new construction and expansion. The Library of Congress is no longer the original reference library serving only Congress, but the largest comprehensive library in the world today. It has 22 reading rooms, 115 million collections (including about 20 million books), a total length of bookshelves of about 860 kilometers, 31,000 collections are replenished every day, and a large number of irregular donations. The library has 5000 staff members, of which about 900 work directly for the Senate and House of Representatives.