Dent has been compared to American historian Francis Parkman for his ability to write about Canadian history without being dull and dry.
Dent received his primary education in Canadian schools, studied law in Brantford, Ontario, and became an attorney in 1865.
In 1880, soon after the death of George Brown, founder of the Globe, Dent severed his connection with that paper and began his first ambitious undertaking, The Canadian Portrait Gallery (1880), which ran to four large volumes.
It contained biographies of Canadian public figures, living and dead, carefully prepared, and written without partisanship.
Through careful research, Dent was able to throw new light on the characters of the men who took part in the Upper Canada Rebellion.
He believed that a true story should be told as agreeably as a fictitious one; "that the incidents of real life, whether political or domestic, admit of being so arranged as, without detriment to accuracy, to command all the interest of an artificial series of facts; that the chain of circumstances which constitute history may be as finely and gracefully woven as any tale of fancy."