Officials say the arrests follow a multi-year joint investigation, which is far from over.
"Our investigation uncovered rampant trafficking of crack, cocaine, fentanyl, and heroin in Chester, as well as an open conflict," said U.S. Attorney William McSwain.
McSwain says more than 300 officers from the FBI, U.S. Marshals, DEA, Chester police, Pennsylvania State Police and more worked together to bust rival gangs 3rd Bone and the William Penn Boys.
"This was an inherently dangerous undertaking, but thankfully all the arrests occurred without incident," McSwain said.
McSwain says it took them three years to take down the two gangs, and these groups listened in on police activity on scanners and flaunted their works on social media.
Authorities say the two groups controlled adjacent territories in the western part of Chester, distributing drugs to customers, and defending their turf with armed violence.
"At times, it actually reads like a Hollywood storyline," McSwain said, "with one notable exception: The facts here were all too real for those living in this area of Chester who had to put up with this criminal activity."