Sentence:  ... she was one of my Master's Captives. For this Reason, I presume, it was, that she took so much Compassion upon me; considering herself a Slave in a strange Country, and only <WSD>preferr'd</WSD> to my Master's Bed by Courtesy. 
Meaning of the word marked with <WSD> tags:  To advance, promote (someone or something). (from 14thc.)