Robertson was the son of ironstone miner Sam Robertson and his wife Elizabeth Neilson. He was one of a number of siblings including his brother Sam who was born at Rosewell on 4 April 1878. After retiring as a professional footballer, he decided to emigrate to the United States and in July 1905 he set sail on the Furnessia. He went to live and work in
Benld, Macoupin County, Illinois. Peter worked there as a miner for the Superior Coal Company of Sawyerville. Peter, who never married, died aged 53 on 4 February 1929 in St Francis Hospital, Litchfield, Illinois after a long illness. Sam Robertson, his brother, joined
Cowdenbeath in 1900 and also did well. In 1901, he joined
Raith Rovers and then in 1902 teamed up with Peter at
Dundee. Sam then came back to play for Cowdenbeath in 1903 as a full back. He was Cowdenbeath's captain. In 1905, he went down to England and played for
Nottingham Forest's local rivals
Notts County for a short time. He went to Benld in 1908 and accompanying Sam and his brother Willie on the trip was another ex-Cowdenbeath player, Jim Paton (who had also played with Notts County). Peter Robertson at one time lived in the US with a John Hynd who had been a goalkeeper with Cowdenbeath and
Newcastle United in England. Pete Nisbet another Cowdenbeath stalwart of that era also moved to the US and settled in Benld. Sam Robertson died in Staunton, Macoupin County, Illinois on 1 November 1952. ==References==