Located several miles outside of Gotham City in Sommerset, the marshland region known as Slaughter Swamp is a place with a grisly history. In 1895, an unscrupulous millionaire named Cyrus Gold carried on an affair with a local prostitute named Rachel Rykel. According to Rykel, she was pregnant with Gold's child, and sought to extort money from him for her silence. Cyrus met with her for a secret negotiation at Slaughter Swamp, several miles outside of Gotham. When Gold refused to yield to blackmail, Rachel's pimp, Jem, dashed Cyrus across the back of the head with a shovel. They buried Gold in the swamp, content that no one would ever come looking for him. Over the span of fifty years, Gold's body interacted with the detritus and sour vegetation of the swamp. Through an as of yet unknown process, Cyrus Gold's corpse transformed into a rotting, vegetative undead monstrosity that the world would soon come to know as Solomon Grundy.
The swamp saw little activity for the next several decades, but in the Autumn of 1944, Gold's zombie rose from Slaughter Swamp, whereupon he went on a savage rampage resulting in the deaths of eleven people. Gold (now known as Solomon Grundy) has been destroyed many times over the last half a century, but invariably, he always rises anew from the depths of Slaughter Swamp.
In recent years, Slaughter Swamp has been incorporated as part of the Slaughter Swamp State Park, with guided tours taking place daily. One of these tours resulted in great tragedy as Solomon Grundy rose from the swamp attacking an innocent tour group. Tour guide Karin Rykel (a possible descendant of Grundy) attempted to protect the young children in her group, but lost her life when the swamp monster crushed her skull with a savage backhand.
- In Pre-Crisis Earth-Two continuity, Cyrus Gold was murdered in the year 1894. In Post-Crisis continuity, his death took place in 1895.
- Although Slaughter Swamp is always associated with Gotham City, it is actually located several miles outside of the city.
- In Issue #4 of the 2009 Solomon Grundy miniseries, it is revealed that Slaughter Swamp's geographical coordinates are Latitude 42"37'N Longitude 71.03W. The real world coordinates place it just outside Logan International Airport in Boston, MA. This could be an arbitrary coordinate that creator Scott Kollins came up with on the fly, or it reflects the notion that DCU's New Earth is slightly larger in order to accommodate the extra fictional cities and countries (as shown in the JLA/Avengers miniseries); many sources place Gotham City (and nearby Slaughter Swamp) in the state of New Jersey.
- All-American Comics #61
- Batman: Shadow of the Bat #39
- Who's Who: The Definitive Directory of the DC Universe #21