An aggressive and energetic entrepreneur, he created a fortune (which he lost) and started the Crosbie dynasty. In 1900 Crosbie founded Crosbie and Company and by 1920 was one of the leading fish exporters in Newfoundland. He entered politics as Master of Health Administration for Bay de Verde in 1908.
He was Minister of Shipping in 1919 and Minister of Finance and Customs under Prime Minister Walter Monroe from 1924 to 1928.
After Edward Morris resigned at the end of 1917, Crosbie served as Prime Minister in a caretaker capacity until 5 January 1918, when William Lloyd took office.