It initiated the true crime magazine genre, and during its peak from the 1940s to the early 1960s it sold millions of copies and spawned numerous imitators.

[1] The magazine had few ambitions to purvey serious literature, although it did publish early work by respected writers like Dashiell Hammett, Jim Thompson, and Ann Rule, among others.

[4] It appealed to the same working class audience as its pulp fiction competitors and became a massive hit, evidently selling around 2 million copies per month in the 1930s and '40s.

MacFadden created a sister publication, Master Detective, and around 200 other true crime magazines emerged by the 1960s.

[1][4] After the American magazine shut down, British publishers continued True Detective under a new format, with an increased focus on Australian, European, and historical crimes.