Sentence:  There were two kinds of redemptioners—‘indented servants,' who had bound themselves to their masters for a term of years previous to leaving Europe, and ‘<WSD>free-willers</WSD>,' who allowed themselves to be sold on arrival to defray the cost of passage to America. 
Meaning of the word marked with <WSD> tags:  An immigrant to the United States who, upon arrival, voluntarily became an indentured servant.