I remember my father used to tell me when I was young. He knows the 后人 of 张英 (Qing prime minister? )from 安徽桐城。 张 family had a fight with the next door neighbor for the three feet of their property line when their neighbor, also a Qing official, was building a new house. Zhang's family wrote an urgent letter to Zhang asking for help. Zhang wrote a letter back, saying: 千里家书只为墙，让他三尺又何妨，万里长城今犹在，不见当年秦始皇。It became 张家之祖- (don't know how to pinxin that one).
