Quarry was created in 1971 while author Max Allan Collins was a student at the Iowa Writer's Workshop, and later appeared in four novels between 1976 and 1977, with a 5th (and supposedly final) book appearing in 1987. However, in 2006 publisher Charles Ardai of Hard Case Crime appealed to Collins to write a another Quarry novel, which eventually lead to a new series of books featuring the character. As of 2016, HCC has published 7 additional books about the hit man.
The Quan Thang flashback in the season one finale consisted primarily of a single take lasting 7 minutes and 30 seconds.
A handful of local antique car owners were used to stage all the other cars during the shoot in Memphis. The local owners antique cars were used in some shots.
In the first teaser, the song was "You Don't Miss Your Water" by Otis Redding. However, HBO/Cinemax only had the rights for the song for a period of time. Therefore, when the promo was aired/uploaded again (before the series finale of Banshee), the song was changed to "Brighter Day" by Noel McKoy.
Quarry's real name is never revealed in the book series upon which the show is based. The TV show's producers christened him Mac Conway in homage to his author/creator Max Allan Collins, (ie MAC).