Born in Marshfield, Prince Edward Island, originally a livestock farmer, Ferguson spent much of his life in public service; from 1872–1873 he served as a justice of the peace, resigning that position in prior to his first of unsuccessful bid for a position on the PEI Legislative Council.
However, in 1878 he finally succeeded in winning, by acclamation, a seat in the House, a position he defended for twelve years until his resignation in October 1890.
However, on 4 September 1893, he was appointed to the Senate of Canada on the recommendation of John Sparrow David Thompson.
He became influential in federal politics, and in January 1895 was appointed Minister without portfolio in the cabinet of Sir Mackenzie Bowell's government.
Ferguson served representing the senatorial division of Queen's, Prince Edward Island until his death in 1909.