《长腿叔叔》的主角乔若莎是个孤儿，她在一位化名为“约翰•史密斯”的理事帮助下进了大学。由于只见过理事高大的背影，乔若莎便在写给理事的信中将其称为“长腿叔叔”。
I have been thinking about you a great deal this summer; having somebody take an interest in me after all these years makes me feel as though I had found a sort of family. It seems as though I belonged to somebody now, and it’s a very comfortable sensation. I must say, however, that when I think about you, my imagination has very little to work upon. There are just three things that I know: 1. You are tall. 2. You are rich. 3. You hate girls. I suppose I might call you Dear Mr. Girl-Hater. Only that’s rather insulting to me. Or Dear Mr. Rich-Man, but that’s insulting to you, as though money were the only important thing about you. Besides, being rich is such a very external quality. Maybe you won’t stay rich all your life; lots of very clever men get smashed up in Wall Street. But at least you will stay tall all your life! So I’ve decided to call you Dear Daddy-Long-Legs. I hope you won’t mind.
这个夏天，我经常在思考关于您的事情。这么多年以来，终于有人眷顾到了我。我不禁觉得，自己好像是找到了某种类似于家的东西，好像是已经有所归属。这种感觉虽然很让人舒服，可我也不得不承认，想到您的时候，我的想象力几乎无从发挥。关于您这个人，我只知道三件事情： 1. 您个子很高； 2. 您很有钱； 3. 您讨厌女孩子。 我曾经想过要叫您“亲爱的讨厌女孩子的先生”，可是，那样的称呼对我来说是一种侮辱。我还想过要叫您“亲爱的有钱人先生”，可是，那样的称呼对您来说又是一种侮辱，就好像您身上唯一值得一提的就是有钱一样。更何况，有钱只是一种非常外在的品质。您兴许不会一辈子都有钱，不少聪明人都在华尔街赔得倾家荡产哩。不过，您个子很高，这一点至少是一辈子都不会变的！所以呢，我决定叫您“亲爱的长腿叔叔”，希望您不会介意。