[1] As a young man he frequently played Glasgow's Theatre Royal, notably as Albert in Sheridan Knowles' William Tell.
In 1863 he came with Mr and Mrs Kean to Australia, making their first appearance at the Haymarket Theatre, Melbourne, in a tour that lasted nine months before moving on to San Francisco in the Fanny Smale, then more in London and the English provinces.
Kean died in 1868 and Cathcart joined Barry Sullivan, remaining with him for seven years, playing in both England and America.
Then he was called to Australia by his sister Fanny, in April 1879, and subsequently played with most of the significant theatre companies of the time: George Rignold, Williamson and Musgrove, Brough and Boucicault, and Charles Holloway.
[1] He died at his home, "Wilcannia", Charnwood Road, St Kilda, Victoria, and his remains interred in the Boroondara Cemetery.