colnect.com
Letter Rate 3¢ Package Rate 3¢ Postcard Rate 1¢ Effective 7/6/1932 United States 6/21/1948 First LP Phonograph Introduced Columbia Records introduced the 33 1/3 RPM long playing phonograph invented by Peter Carl Goldmark. This LP allowed up to 20 minutes per side and was available in 10 and 12 inch versions. It was shown at the Waldorf-Astoria Hotel in New York City. American President Harry S Truman (4/12/1945-1/20/1953) British Prime Minister Clement Attlee (7/26/1945-10/26/1951)