A player with Newton Heath, the forerunners of Manchester United, he began his managerial career at Barnsley, where he had complete control of team affairs, which was unusual at the time. Despite improving the club’s financial position, he sold Benny Green to Birmingham City and the team’s form slumped dramatically.
The Glasgow-born McCartney returned north of the border to manage St Mirren and took them to the Scottish Cup Final and runners-up in the First Division on two occasions. He then managed Heart of Midlothian for 10 years before moving south to take charge at Pompey in 1920. Whilst manager of Heart of Midlothian he played a pivotal role in the team being the first to enlist en masse for WW1 and the formation of the McRae’s Sporting Battalion. In November 1914, Hearts led the Scottish First Division. In the middle of a debate about the morality of continuing professional football during the First World War and a campaign to shame footballers into joining up, eleven Hearts players enlisted in Sir George McCrae’s battalion on 25 November. Hearts supporters and players and supporters from myriad other clubs flocked to join as well. Officially known as 16th Royal Scots, this unit was the first to be described as a footballers battalion. On 1 July 1916, 15th and 16th Royal Scots attacked near the village of Contalmaison in the Somme Valley. Three Hearts players would die that day; seven would be killed in total during the war, and many more would be wounded.
Soon after Pompey were in the First Division after pipping Manchester City to second spot by the narrowest of margins but in May fo 1927 he had to resign because of ill health. However, four months later, he took over at Luton Town where he had played but again he was dogged by ill health and finally forced his resignation and retirement from football.
There was plenty of affection for this hard-working manager and the launching of a testimonial fund quickly raised £300. In January 1933 John McCartney died and was buried just a short distance from Heart of Midlothian’s ground where both he and his brother, Willie, had been successful managers.