EVB2937527: Students and their teacher watch educational television in a school library in Schenectady, New York, 1954 / Bridgeman Images

EVB2937530: New York City's Manhattan's skyline shrouded in darkness, is offset by the lights of a freighter at a Brooklyn pier. On November 9, 1965, the lights went out for 12 hours in the Northeast States and Canada / Bridgeman Images

EVB2937536: Electric lamps on display in a store in the Washington, D.C. area. c. 1920 / Bridgeman Images

EVB2937542: Workmen pose for a group portrait on the giant turbine in the powerhouse of the Bonneville Dam. c. 1937 / Bridgeman Images

EVB2937584: Four workers riding on a large casing section of pipe suspended from cable as it is moved into position during construction (1933-42) of the Grand Coulee Dam, Washington / Bridgeman Images

EVB2937599: Close-up of switches in the control room of Reactor B, the first large scale nuclear reactor ever built. Photo from the Hanford Site of the Manhattan Project, c. 1942-44 / Bridgeman Images

EVB2937605: A model of Sputnik 1, International Geophysical Year, 1957 / Bridgeman Images

EVB2937614: ECHO I, NASA's first communications satellite, was a passive spacecraft based on a Mylar balloon design. Launched in 1960, ECHO I expanded to a balloon with a 100 foot diameter that reflected radio transmissions from one ground station back to another / Bridgeman Images

EVB2924142: The front wall of the Wilfong Fireworks Co., after it exploded, injuring 13 people, Fort Worth, Texas. June 19, 1953 / Bridgeman Images

EVB2924145: Second Italo-Ethiopian War. Ras Nassibu's Ethiopian Army marching out of Harrar to stop the advance of Italian forces under General Rudolfo Graziana. Nov. 1935 / Bridgeman Images

EVB2940336: Firefighters and search and rescue teams work on 'The Pile' of rubble from the collapsed World Trade Center. In back ground is one of the buildings of the damaged World Financial Center. Sept. 16 2001 / Bridgeman Images

EVB2924169: Dust mask developed for workers. 1935 / Bridgeman Images

EVB2940384: President Ford the Republican nominee shakes hands his challenger Ronald Reagan on the closing night of the Republican National Convention. Also on stage are VP nominee Robert Dole Nancy Reagan VP Nelson Rockefeller Susan Ford Betty Ford. Aug. 19 1976, Unknown photographer, (20th century) / Bridgeman Images

EVB2940411: New Orleans after Hurricane Katrina showing a levee break under repair and flooding on one side with the other intact and dry. Sept. 2005 / Bridgeman Images

EVB2924259: Aerial view of Brandenburg Gate, where the Berlin Wall forms a loop. East Berlin stretches into the distance. Aug. 6, 1969 / Bridgeman Images

EVB2924271: First Days of the Berlin Wall. West Berliners jeer East German soldiers patrolling the new barbed wire barricades closing streets between the Russian occupied sector and the French, British and U.S. zones. August 13, 1961 / Bridgeman Images

EVB2940474: Mount St. Helens on its first day of eruption on May 18 1980 sent volcanic ash steam water and debris to a height of 60 000 feet / Bridgeman Images

EVB2940492: Dramatic view of the Arctic Ocean ice during the summer melt. Sept. 9 2009 / Bridgeman Images

EVB2924337: Harold Hickerson demands Bonus payment. Speaker of the House John Nance Garner, listens as Bonus Vets Spokesman read a petition demanding early bonus payment. Feb. 14, 1932 / Bridgeman Images

EVB2940516: Hurricane Andrew blew into south Florida at Category 5 strength. In Dade County 90 of homes had roof damage and 117 000 were destroyed or had major damage. August 1992 / Bridgeman Images

EVB2924346: Bonus Army entrepreneur. African American veteran from Detroit, Charles Wood, opened a store in Bonus City. His funny signs enlivened his tattered salvaged inventory. Fellow veteran Anthony Parmigini bought a pair of shoes. June 16, 1932 / Bridgeman Images

EVB2940525: A breech in a New Orleans levee floods neighborhoods the day after the Hurricane Katrina hit the city. August 30 2005 / Bridgeman Images

EVB2940555: Constitution of the United States of Americ. Second of four pages of the National Archives copy created in the Constitutional Convention in 1787 / Bridgeman Images

EVB2924361: Prohibition ended and gentlemen enjoyed their beer on April 7, 1933. Three weeks earlier, President Franklin Roosevelt signed the Cullen-Harrison Act. It amended the Volstead Act and allowed the manufacture and sale of '3.2 beer' and ligh t wines. / Bridgeman Images

EVB2940573: John Tyler receiving the news of President Harrison's death, [April 5, 1841] / Bridgeman Images

EVB2940585: Map of the Proposed Lock Haven and Tyrone Rail Road. 1857 / Bridgeman Images

EVB2935533: Captain Bruce Bairnsfather (1888-1959), Indian born British cartoonist who created the character of Old Bill, a grumpy, trench-weary World War I soldier. 1918 portrait by Pirie MacDonald, Unknown photographer, (20th century) / Bridgeman Images

EVB2935557: Grandma Moses, born as Anna Mary Robertson (1860-1961), began painting in her seventies and achieved acclaim as a folk painter. c. 1950 at age 90 / Bridgeman Images

EVB2935563: Cecil Beaton (1904-1980), kneeling on mantle of fireplace to take photograph of Lilyan Tashman (1899-1934), movie actress, reclining on chaise in Hollywood, California. c. 1930 / Bridgeman Images

EVB2935575: Antoine Lumiere (1840-1911), father of the famous Lumiere brothers, Auguste and Louis, partnered with his sons in their early efforts to develop motion pictures. 1907 portrait by Pirie MacDonald / Bridgeman Images

EVB2935593: Jo Davidson (1883-1952), Russian American sculptor at work on a marble plaque in his studio, beneath the shelf bearing replicas of his famous portrait busts. c. 1940 / Bridgeman Images

EVB2935599: Service station in Avon, Pennsylvania with gasoline pumps and station attendants. c. 1940s / Bridgeman Images

EVB2935626: Helen Adams Keller (1880-1968), wearing academic cap and gown in 1904. Keller was blind and deaf, and her education broke barriers for the disabled / Bridgeman Images

EVB2935638: Walter W. Liggett (1886-1935), crusading Minnesota journalist and newspaper publisher waged a journalistic campaign against 1930's organized crime and corrupt politics, was assassinated on December 9, 1935 / Bridgeman Images

EVB2935650: T. E. Lawrence (1888-1935) was an enthusiastic motorcyclist and died from injuries of a motorcycle accident in 1935, Unknown photographer, (20th century) / Bridgeman Images

EVB2933129: Ravi Shankar (b. 1920), playing the sitar. Shankar increased Western appreciation of traditional Indian music. 1957 / Bridgeman Images