Sentence:  Manchester 's unusual interest in telegraphy has often been attributed to the fact that the Rev. J. D. Wickham , headmaster of Burr and Burton Seminary , <WSD>was</WSD> a personal friend and correspondent of the inventor , Samuel F. B. Morse . 
Meaning of the word marked with <WSD> tags:  have the quality of being; (copula, used with an adjective or a predicate noun)