But it is worth remembering there were many who were vehemently opposed to the idea of fighting and dying for king and country.
In Glasgow, one man stood head and shoulders above the rest - John MacLean.
He was born into a working class family in Pollokshaws and went on to espouse socialism and become one of the leading figures among the Red Clydesiders.
His working life was spent in education but he devoted his efforts to agitating against the First World War.
In a speech to the court during his famous trial for sedition he said: "I am not here as the accused; I am here as the accuser of capitalism dripping with blood from head to foot."
MacLean was jailed for his beliefs. In Peterhead Prison he went on hunger strike and was force-fed twice daily using a stomach tube.
His wife Agnes wrote that MacLean was being subjected to torture and described the feeding process as "slow murder".
After the war he was released from prison to great public fanfare. Songwriter Hamish Henderson in the John MacLean March wrote that "Great John MacLean has come hame tae the Clyde".
Matt McGinn wrote of him as the "fightin' dominie" and 90 years after his death at the young age of 44 he is still revered in Glasgow as a champion of the left.
The statue pictured was erected in Pollokshaws, beside the old Pollokshaws Town Hall in Pleasance Street.
The plaque reads: "In Memory of John MacLean, born in Pollokshaws 24th August 1879. Died 30th November 1923. Famous pioneer of working class education. He forged the Scottish link in the golden chain of world socialism."
There is at least one other memorial to MacLean in Glasgow, a plaque in Candleriggs in the Merchant City.