Sentence:  Author of the Albany Plan of Union , which , had it been adopted , might have avoided the Revolution , he <WSD>fought</WSD> the colonists ' front-line battles in London , negotiated the treaty of alliance with France and the peace that ended the war , headed the state government of Pennsylvania , and exercised an important moderating influence at the Federal Convention . 
Meaning of the word marked with <WSD> tags:  be engaged in a fight; carry on a fight