James Sadler worked as a clerk in the Education Department and as an inspector for the Savings Bank of South Australia. He was an active member and office-holder in the Adelaide Literary Society.
In 1892 he went to London as London correspondent of the South Australian Register, a position he held for about twenty years. During this time he travelled extensively in Europe, America and Northern Africa, contributing articles to The Register on these trips. In 1913 he was appointed Publicity Officer of the State Recruiting Committee of South Australia, and in this capacity he published The Joy of the True Soldier [1914] which includes a poem.
Some of Sadler's articles from The Register were also published separately: Art and Patriotism (1917), A Word for Mr Bumble (1918).