Most of the original collection was burnt by the British during the War of 1812, with the library beginning efforts to restore its collection in 1815. The library purchased Thomas Jefferson's entire personal collection of 6,487 books, and its collection slowly expanded in the following years, although it suffered another fire in its Capitol chambers in 1851. This destroyed a large amount of the collection, including many of Jefferson's books. After the American Civil War, the importance of the Library of Congress increased with its growth, and there was a campaign to purchase replacement copies for volumes that had been burned. The library received the right of transference of all copyrighted works to deposit two copies of books, maps, illustrations, and diagrams printed in the United States. It also began to build its collections. Its development culminated between 1888 and 1894 with the construction of its own separate, large library building across the street from the Capitol. Two additional buildings have been constructed nearby to hold collections and provide services, one in the 1930s and one in the 1970s.