Established as a legislative library in 1800 to support the U.S. Congress when it moved from Philadelphia to Washington, D.C., the Library of Congress—retaining its original name and primary legislative purpose—has subsequently become the largest and most international of the world's major libraries. The principal reason is that Librarians of Congress since Ainsworth Rand Spofford (1864–97), but especially Herbert Putnam (1899–1939), Luther H. Evans (1945–53), and James H. Billington (1987–), have affirmed and expanded Thomas Jefferson's concept that the Library of Congress is a national institution that should be universal in scope and widely and freely available to everyone.