The Library of Congress was the largest library in the United States during the 19th century and housed an extensive collection of books and manuscripts. On December 22, 1851, a devastating fire broke out in the building. The blaze began in the basement, sparked by a defective stove, and rapidly spread throughout the library, overwhelming the firefighting efforts of the time. Despite the best efforts of firefighters, the fire consumed an estimated 35,000 books, approximately two-thirds of the library's holdings, which included rare and invaluable texts. Among the most significant losses were over 6,000 volumes from Thomas Jefferson's library, which had been sold to the library after the British burned the original congressional collection in 1814.The aftermath of the fire prompted a reevaluation of the Library of Congress's facilities and fire prevention measures. Congress responded by providing funding for the rebuilding of the library, which included better fire safety features. A new building was constructed to house the library's growing collection, and in 1897, the current Jefferson Building was completed. This event marked a pivotal moment in the history of the Library of Congress, emphasizing the importance of conservation and protection of cultural heritage.