Songfacts®:

• "English Civil War" is actually a re-arrangement of a traditional American Civil War song, "When Johnny Comes Marching Home" (this title is mentioned in the lyrics), which was originally written by a Massachusetts Unionist, Patrick Sarsfield Gilmore, and which became popular with both sides in the war and eventually became associated with the Confederates. Hence why the song is credited as "trad. arr. Strummer/Jones" rather than just a Strummer/Jones composition.
• When interviewed about this song singer Joe Strummer noted that he learnt "When Johnny Comes Marching Home" at school. "It was such a good tune. I suggested that we update it, see what it sounded like," he said.
• The lyrics, passionately delivered by Joe Strummer, discuss the band's fears about the rise of the National Front and radical, fascist far-right-wing politics in the UK, and fears that this will cause tensions and riots on the streets. In a discussion with Terry Lott of Record Mirror magazine after the song's live debut at the April 1978 Rock Against Racism festival in Victoria Park, Joe Strummer speculated that "War is just around the corner. Johnny hasn't got far to march. That's why he's coming by bus or underground (referencing part of the lyrics). It's a folk song, that's all."
  
  In the same interview the band were asked whether they were exaggerating the power of the National Front and racist groups, and guitarist Mick Jones replied: "In 1928, Adolf Hitler got 2.8% of the vote. In 1939 there was no one voting for anyone else."
• Along with being based on a traditional American Civil War song, "English Civil War" references (as the title suggests) the English Civil War of the 1640s-50s, in which King Charles I was defeated by the Parliamentarians and Britain became a Republic for the first (and only) time in it's history. Oliver Cromwell's New Model Army (the Parliamentarians) are referenced in the line, "the new party army was marching right over our heads."
• This song was recorded much in the same way as the other tracks on Give 'Em Enough Rope, using a series of interlocking guitar parts assembled and overlaid. Unusually Mick Jones has two rather extravagant solos, unusual for a Punk Rock song in which solos and over-the-top instrumentation were heavily shunned.
  
  The single release in January 1979 featured a still from the classic animated film adaptation of Animal Farm from 1955, and was reviewed by Danny Baker for NME, who concluded that it was a "wise enough, if a miscued and rock 'n' rolly, warning of all things uniformed and sinister."
• This was a popular live song, and a fixture of The Clash's live set between 1978-1980, before being included only occasionally thereafter - notably at their arena tour in 1982 supporting The Who.
  
  During the 1979 Take the Fifth US tour, the Clash tried an interesting experiment and played the song in a slow, acoustic folk style much like the original folk song it was derived from. Some US fans were disappointed and booed the band "for not sounding like Ted Nugent," according to Strummer.
  
  One of the deleted scenes from the Clash docu-drama Rude Boy movie is a hugely energetic version of the song played at the Lyceum in January 1979 (the same show that the version of "I Fought The Law" from near the end of Rude Boy comes from), and was included as a bonus feature on the DVD re-release in 2001, as well as the Clash on Broadway compilation CD.
• The folk-rock band The Levellers (ironically named after a faction of Cromwell's New Model Army) covered the song for their 1993 EP The Julie.