Historical Fiction Setting.

Any book relies heavily on the setting to affect the plot and the characters, especially historical fictions because they take place in a completely different time period.  Stories are also greatly affected by the physical place in which it is set, especially historical fictions because the history in one place can be completely different from the history in another place during the same time period.   How does the setting - time and place - of your novel affect your story?  Make sure to back you answer up with specific examples from the book.