In which decade was the song 'White Christmas' written?

"White Christmas" is a 1942 Irving Berlin song reminiscing about an old-fashioned Christmas setting. According to the Guinness World Records, the version sung by Bing Crosby is the best-selling single of all time, with estimated sales in excess of 100 million copies worldwide. Other versions of the song, along with Crosby's, have sold over 150 million copies.

The first public performance of the song was by Bing Crosby, on his NBC radio show The Kraft Music Hall on Christmas Day, 1941. A copy of the recording from the radio program is owned by Crosby's estate and was loaned to CBS News Sunday Morning for their December 25, 2011, program. He subsequently recorded the song with the John Scott Trotter Orchestra and the Ken Darby Singers and Chorus for Decca Records in just 18 minutes on May 29, 1942, and it was released on July 30 as part of an album of six 78-rpm discs from the musical film Holiday Inn. At first, Crosby did not see anything special about the song. He just said "I don't think we have any problems with that one, Irving."