Qian had the prerogative to choose who, what, why and how things happened in his history.
Qian chose to quote his sources as much as possible. An example is the account of the attempt made by Jing Ke on the life of the first Chinese emperor, which was an eyewitness account by the great-grandfather of his father's friend, who served as a low-ranked bureaucrat at court of Qin and happened to be attending the diplomatic ceremony for Jing Ke. Qian also created highly probable and consistent events even when there were none available.
His work eventually consisted of 130 chapters about Dynastic houses, the biographies of the Han emperors, dates of events, descriptions of rites and rituals, music, and various other topics of interest. Also included were the histories of the states which existed during pre-Qin China and the biographies of other important personages in history.
Before The Records of the Grand Historian, historical texts tended to downplay the role and events from other dynasties and played up their own. This tendency was also present in Sima Qian's historiography. Qian portrayed the Han dynasty as having the Mandate of Heaven and gave lesser importance to the dynasties that preceded it.
Among the features that Qian emphasized in his work was the ascendant character of the Han Dynasty. ...