Deadpool Vs. X Force by Duane Swierczynski

An irreverent, time-hopping clash erupts when the Merc with a Mouth is hired to “improve” U.S. history, ricocheting through the Revolutionary War, the Civil War, and beyond while warping the timeline. Cable rallies his early black-ops team to chase him across centuries, trading quips and gunfire as they try to contain cascading paradoxes and uncover the shadowy benefactor behind the mission. As the skirmishes escalate, both sides are forced to confront the consequences of rewriting the past and the surprising motives driving the chaos.