The frequent collaborators will be writing a new ongoing series alongside artists Travis Moore and Trevor Scott.
Freedom Fighters stars a group of patriotic American heroes lead by Uncle Sam, who were first incorporated by DC pre-Crisis into a world where the Allies had eventually lost a protracted World War II.
"[The Freedom Fighters are] an interesting and unique team of heroes, not just because of the political elements we can inject into stories, but also from the fact that they've been around for such a long time but haven't been given a big enough stage to shine on," Gray told CBR.
"This time around, we've been focusing on giving them their own rogues and revamping existing ones in interesting ways. They're patriotic heroes to a degree, but the potential to tell very different kinds of stories exists with this team more so than others.
"I think, from a reader's perspective, you don't know what to expect and there aren't a strict set of rules to follow."
The first arc introduces a storyline focusing around a weapon of mass destruction created by the Confederates during the American Civil War.
Palmiotti and Gray previously wrote the team in Crisis Aftermath: Battle for Bludhaven and later in two miniseries titled Uncle Sam and the Freedom Fighters and Freedom Fighters.
The ongoing series will debut in September.