President William Howard Taft on the phone. Taft was the 27th U.S President serving from 1909 – 1913.(Photo by Harris & Ewing Collection/Library of Congress)

President Woodrow Wilson speaks on telephone. Woodrow Wilson was the 28th U.S. President serving from 1913 – 1921. (Photo by Corbis)

President Calvin Coolidge speaks on the telephone in 1928. John Calvin Coolidge, Jr was 30th U.S President serving from 1923 – 1929. (Photo by Harris & Ewing Collection/Library of Congress)

President Harry Truman talks on the telephone in his office, Washington D.C., 1945. Harry S. Truman was the 33rd U.S. President serving from 1945 – 1953. (Photo by Corbis)

President John F. Kennedy is shown as he ends his official day after 7:30 pm with a final phone call to his press secretary from his Oval Office desk at the White House in Washington, D.C., March 16, 1961. Spread on the desk are copies of his newly designated official portrait which he autographed. John Fitzgerald Kennedy was the 35th U.S. President serving from 1961 until his assassination in 1963. (Photo by Henry Burroughs/AP Photo)

President Lyndon Johnson talks on the telephone at the White House in Washington, D.C. on an unknown date. Lyndon Baines Johnson was the 36th U.S. Presdident serving from 1963 – 1969. (Photo by AP Photo/LBJ Library)

President Lyndon Johnson talks on the telephone from the Oval Office in 1964. Lyndon Baines Johnson was the 36th U.S. Presdident serving from 1963 – 1969. (Photo by Yoichi r. Okamoto/AP Photo/LBJ Library)

President Richard Nixon speaks to astronauts on the Moon on July 20, 1969. Richard Milhous Nixon was the 37th U.S. President serving from 1969 – 1974. (Photo by Corbis)

President Gerald Ford, seated in an armchair with his foot on the desk, talking on the telephone in the oval office, Washington, D.C. circa 1974. Gerald Rudolph “Jerry” Ford, Jr. was the 38th U.S. President serving from 1974 – 1977. (Photo by Consolidated News Pictures/Getty Images)

President Gerald R. Ford takes a phone call while his daughter Susan Ford adjusts her father's cummerbund before a white tie diplomatic reception on October 5, 1974, in Washington, D.C. (Photo by David Hume Kennerly/ Getty Images)

President Jimmy Carter speaks on the phone in the Oval Office in Washington, DC. James Earl “Jimmy” Carter, Jr. was the 39th U.S. President serving from 1977 – 1981. (Photo by Corbis)

President Ronald Reagan telephones Vice President Bush at 5:58 a.m. regarding the Grenada situation from the White House, Washington, DC on October 22, 1983. Ronald Wilson Reagan was the 40th U.S. President serving from 1981 – 1989. (Photo by Corbis/Bettmann)

President George H. W. Bush, left, speaks to the orbiting Columbia astronauts with Vice Pres. Dan Quayle from the Oval Office, Thursday, Jan. 18, 1989, Washington, D.C. George Herbert Walker Bush was the 41st U.S. President serving form 1989 to 1993. (Photo by Ron Edmonds/AP Photo)

President Bill Clinton speaks via telephone from the Oval Office of the White House to an unidentified member of the House in Washington Thursday, August 11, 1994, lobbying for votes for the crime bill. The White House kept an open telephone line to the Democratic cloakroom so the President could personally woo wavering lawmakers. Willam Jefferson Clinton was the 42nd U.S. President serving from 1993 – 2001. (Photo by Marcy Nighswander/AP Photo)

President George W. Bush speaks to Canadian Prime Minister Jean Chretien on the telephone in Washington Sunday, Oct. 7, 2001. Chretien was one of several world leaders Bush spoke to before telling the United States and the world of air strikes against the Taliban. George Walker Bush was the 43rd U.S. President serving from 2001 – 2009. (Photo by Eric Draper/AP Photo/The White House)

President Barack Obama talks on a phone with Afghanistan's President Hamid Karzai from his vehicle outside the Jane E. Lawton Community Center in Chevy Chase, Maryland, in this handout photograph taken and released on March 11, 2012. (Photo by Pete Souza/Reuters)