The lyrics are written from the perspective of a person welcoming home their spouse at the end of the war.

The most popular recording, by trumpeter Harry James and His Orchestra with vocalist Kitty Kallen,^[1] debuted in October 1945 on Billboard's Best-Selling Popular Retail Records chart and reached number one in the chart dated November 24, 1945 – the last of Harry James's nine US number ones.^[2] The record features a solo by alto saxophonist Willie Smith.

A hit version by iconic crooner Bing Crosby with Les Paul and His Trio^[3] (recorded on July 12, 1945)^[4] debuted the same week as James's record, which it replaced at number one in the chart dated December 8, 1945.^[5] Sammy Kaye's "Chickery Chick" then returned to number one, only to be replaced by the Harry James recording, which reclaimed the top spot (for one final week) in the chart dated December 22. James's and Crosby's hits remained on the chart for 17 and 16 weeks, respectively. Both versions reached number one^[3] on Billboard's Records Most-Played on the Air chart and its Most-Played Juke Box Records chart.

Two other recordings of "It's Been a Long, Long Time" charted in America in late 1945: Charlie Spivak and His Orchestra with vocal by Irene Daye (US no. 4)^[6] and Stan Kenton and His Orchestra with vocal by June Christy (US no. 6).^[7]

"It's Been a Long, Long Time" topped Billboard's composite Honor Roll of Hits chart for the last seven weeks of 1945.

Les Paul recalled in an interview for Mojo magazine that "Bing was a sucker for guitar and that particular song was a case of you don't have to play a lot of notes, you just have to play the right notes."^[8]

The song became a standard with versions recorded by The DeMarco Sisters (1945),^[9] June Haver and Dan Dailey (1950), Perry Como (1956), Al Hibbler (1956), Peggy Lee (1959), Keely Smith (1959), Louis Armstrong (1964), and Tom Jones (1966). In 1945 Frank Sinatra sang a version on the radio show Your Hit Parade, and this recording has appeared on many compilation albums. Harry James and His Orchestra re-recorded the song with singer Helen Forrest.

Others who have recorded it include Doris Day (on her 1965 album Doris Day's Sentimental Journey), Guy Mitchell,^[10] Sammy Cahn, Shelley Fabares (on her 1962 album Shelley!), Sammy Kaye, The Ink Spots, Pentatonix, Tina Louise, Jimmy Roselli, Brook Benton, Judy Kuhn, Rosemary Clooney, Chet Atkins with Les Paul (on their 1976 album Chester and Lester), Brent Spiner (on his 1991 album Ol' Yellow Eyes Is Back) and Pete Fountain (on his 1966 album A Taste of Honey).

• The Harry James and Kitty Kallen recording features briefly in the beginning of the movie Red Tails (2012), which is about an all African-American team of fighter pilots during World War II.
• The Bing Crosby and Les Paul recording was used throughout the Ken Burns documentary miniseries The War (2007).

Marvel Cinematic Universe edit

The Harry James and Kitty Kallen recording features in multiple projects in the Marvel Cinematic Universe, notable as a tragically ironic piece of music representing Steve Rogers/Captain America (Chris Evans) and his best friend James "Bucky" Barnes (Sebastian Stan) and later with love interest Peggy Carter (Hayley Atwell) being torn apart by time.

• It was first used in Captain America: The Winter Soldier (2014), when Nick Fury (Samuel L. Jackson) is hiding in Steve's apartment after an assassination attempt by HYDRA agents in the streets of Washington DC, before being shot by the Winter Soldier; representing the first instance in which Steve Rogers is reunited with his childhood best friend and companion Bucky Barnes since their separation during World War II (despite the identities of both men not being known to the other).
• The song is used again at the end of Avengers: Endgame (2019) when Steve travels back in time and chooses to live out his life with Peggy. The two share a slow dance to the song – a reference to the dance date Rogers promised Carter right before he was lost in ice for 70 years in Captain America: The First Avenger (2011).^[11][12]
• The song plays during the Marvel Studios intro in "For All Time. Always.", the sixth episode of the first season of the Disney+ series Loki (2021).
• The song is featured in What If... Captain Carter Fought the Hydra Stomper?, the fifth episode of the second season of the Disney+ animated series What If...?. In the episode, which is this universe's substitute for the events of The Winter Soldier, an alternate version of Carter, called Captain Carter and an alternate version of Rogers, who is in a suit of armor called the Hydra Stomper, are reunited after 70 years apart, and have a moment as the song plays in the background.

• Grudens, Richard (2002). Bing Crosby: Crooner of the Century. Celebrity Profiles Publishing Co. ISBN 1-57579-248-6.
• Macfarlane, Malcolm. Bing Crosby: Day By Day. Scarecrow Press, 2001.
• Osterholm, J. Roger. Bing Crosby: A Bio-Bibliography. Greenwood Press, 1994.