求解英语句子的意思.However,a sprawling AP report reveals that Lewinso

求解英语句子的意思.
However,a sprawling AP report reveals that Lewinson,now listed by the FBI as one of the longest held Americans in history,was working for the CIA when he went missing.我只需要知道(one of the longest held Americans in history)是什么意思就可以给分,请给我准确翻译吧.