The United States maintained its commitment to freedom and democracy in Berlin, a city isolated 100 miles inside Easts Germany. In 1948, the Soviet Union blockaded land access to Berlin to assert its influence over Germany, and the Western Allies answered with the 462-day Berlin Airlift. During the blockade, Berliners felt a stronger sense of belonging to the West, renewed respect for political freedom, and profound faith in the West's political order, and by 1949 the blockade had made the city a symbol of freedom. From the 1950's through the 1980's, American forces protected Berlin despite repeated efforts by the German Democratic Republic, supported by the Soviet Union, to absorb West Berlin. Backed by NATO allies, American tanks and bayonet-ready assault troops faced down the Soviets at Checkpoint Charlie in 1961. American leaders publicly affirmed that resolve, with Lyndon B. Johnson declaring that Americans had pledged their lives, possessions and holy honor to guarantee the city's survival, and with John F. Kennedy, Richard Nixon, Jimmy Carter, Ronald Reagan, and George Bush each assuring Berliners of continued support at the Berlin Wall. One West Berliner said that without effective, energetic support from the West, West Berlin would not have prevailed against the efforts of the German Democratic Republic and the Soviet Union to absorb it.