Iron Mountain, an old limestone mine-turned-high-security facility in Pennsylvania, is the unlikely spot where you'll find 150 years of American history packed away in filing cabinets. Millions of photographs, negatives, and even glass plates from 19th Century cameras, are stored in the facility 220 feet underground -- a trove of times gone by. They're the property of Corbis, a company owned by Bill Gates.
Keep clicking to see some of the original images kept there, such as this one of John F. Kennedy and Jacqueline Bouvier. The couple is seen on June 27, 1953, in Hyannis Port, Mass., sitting together in the sunshine at Kennedy's family home a few months before their wedding.
Heavyweight champion Muhammad Ali stands over Sonny Liston and taunts him to get up during their title fight on May 25, 1965. Ali knocked Liston out in one minute in the first round during their bout at the Central Maine Youth Center in Lewiston, Maine.
Pele, of Brazil's Santos soccer team, dribbles the ball down the field of the Coliseum, as Guadalajara, Mexico defensive player Gustavo Pena tries to block him. A crowd of 16,000 was on hand at this game on June 3, 1973. Santos won, 2-1.
Elizabeth Eckford ignores the hostile screams and stares of fellow students on her first day of school on Sept. 6, 1957, in Little Rock, Ark. She was one of the nine African American students whose integration into Little Rock's Central High School was ordered by a federal court following legal action by the NAACP.
Jan. 27, 1961: Jan Murray (L) sits alongside Rat Pack members Dean Martin, Sammy Davis Jr., and Frank Sinatra as the group unwinds backstage at Carnegie Hall after entertaining at a benefit performance in honor of Dr. Martin Luther King Jr.
April 8, 1936: Three photographers in the Roosevelt press corps aim their cameras in Coral Gables, Fla., while awaiting FDR's return from a fishing holiday. From left to right: Johnny Thompson, George Skadding and Joe Jamieson.
Mary Rae Bingham kisses her boyfriend, Gordon Kiester, in the sunshine from a window at Michigan Central Station in Detroit in December 1944. Kiester was about to return to his duties as a sailor after a Christmas holiday break.
The original caption of this photo featuring President Franklin D. Roosevelt reads, "'Cut Yourself a piece of cake," and that's just what FDR did.' Then governor of New York, he was shown as he cut the cake at the celebration of his 50th birthday, Jan. 30, in Statesburg High School in Statesburg, N.Y. The photo shows, left to right, front row - Mrs. Franklin D. Roosevelt, Gov. Roosevelt and Mrs. Sara Delano Roosevelt, the governor's mother. Standing: Mrs. Frances Branigan and Lewis Filkins, Secretary and President, respectively, of the Roosevelt Home Club of Hyde Park.
This photo shows, from left to right: Henry, the Butler, Mrs. Ulysses S. Grant, General Grant, Miss Nellie Grant, Ferdinand, Jesse R. Grant, U.S. Grant, Jr. -- known as "Buck" Grant, and the boy behind Buck Grant is Willie Coles, a friend of the president's son, Jesse, in the 1870s at Long Branch Cottage at Governor's Island, N.Y. The photo was taken by G.W. Pack, of Pack Studios in New York City.
President Abraham Lincoln with Gen. George B. McClellan at his headquarters at Antietam, Va., on Oct. 3, 1862. From left: Gen. George W. Morell, Col. Alexander S. Webb, Gen. McClellan, Scout Adams, Dr. Jonathan Letterman, unidentified officer, President Lincoln, Col. Henry Hunt, Gen. Fitz, John Porter and an unidentified officer.
Teammates Steve Myhra (left) and Carl Tasoff (right) carry Baltimore quarterback Johnny Unitas into the dressing room after the Colts defeated the Giants, 31-16, in the championship game on Dec. 12, 1959.
Audrey Hepburn hugging her Yorkshire terrier, "Famous." Hepburn was calling her actor husband, Mel Ferrer, who was in California. When this photo was taken, Hepburn was in Manhattan filming "Breakfast at Tiffany's."
The airship Hindenburg explodes into a huge ball of fire as it comes in for a landing at Lakehurst, N.J., on May 6, 1937. Miraculously, many of the passengers and crew aboard managed to escape unharmed.
Peggy Fleming, of the Broadmoor Skating Club of Colorado Springs, performs in the Senior Ladies Free Skating competition during the National Figure Skating Championships in Philadelphia in this undated photo.
The original caption on this photo reads as follows: "George Bush Jr. has a 'leg up' on his father, President George Bush, as the President attempts to stretch prior to jogging at Fort McNair. The younger Bush, part owner of the Texas Rangers baseball team, was clowning for photographers."