Sentence:  Next year is the 80 th anniversary of the signing of the treaty between Korea and the United States and experts in Seoul are trying to find the correspondence between Frederick Frelinghuysen , who <WSD>was</WSD> secretary of state in 1883 and 1884 , and Gen. Lucius Foote , who was the first minister to Korea . 
Meaning of the word marked with <WSD> tags:  work in a specific place, with a specific subject, or in a specific function