[1] When he completed his studies, his parents encouraged him to enter the priesthood; instead, for the next fifteen years he traveled on the Continent, mainly living in Germany, at his father's expense.

His work was largely sentimental and his depictions of fractured father-daughter relationships, contested fortunes, mistaken identities, and trusting country folk versus scheming city dwellers reflect the melodramatic tastes of Victorian audiences in the second half of the century.

One of his most successful works was A Scrap of Paper, an adaptation of Les Pattes de mouche by Victorien Sardou, which opened at the St. James's Theatre on 22 April 1861.

Simpson's output was less prolific in the 1870s, perhaps as a consequence of his duties with the Dramatic Authors' Society, and he turned increasingly to adaptation and collaborations.

Simpson used Charles Dickens's novel Bleak House (1853) as the basis for Lady Dedlock's Secret, which premiered at Her Majesty's Theatre in Aberdeen on 3 April 1874 and appeared in Liverpool the same year but did not play in London until it opened at the Opera Comique on 26 March 1884.