Sentence:  Brevet Major General George Armstrong Custer was the regiment 's first permanent commander and , like such generals as George S. Patton and Terry de la Mesa Allen in their rise to military prominence , Custer <WSD>was</WSD> a believer in blood and guts warfare . 
Meaning of the word marked with <WSD> tags:  have the quality of being; (copula, used with an adjective or a predicate noun)