Sentence:  When in 1816 an act of Congress forced the foreign firm out of the United States , its British born employees , <WSD>now</WSD> become American citizens - Joseph Rolette , Joseph Renville and Alexis Bailly - continued in the fur business . 
Meaning of the word marked with <WSD> tags:  in the historical present; at this point in the narration of a series of past events