Sentence:  This trade <WSD>was</WSD> subject to a tariff of 7.5 per cent after February 1835 , but much was smuggled into Assiniboia with the result that the duty was reduced by 1841 to 4 per cent on the initiative of the London committee . 
Meaning of the word marked with <WSD> tags:  have the quality of being; (copula, used with an adjective or a predicate noun)