Which book made you cry happy tears?

I recently finished reading David Copperfield by Charles Dickens. The book is on the larger side and follows the life of the titular character from birth until adulthood. He has some happy moments and many unhappy ones. I think the length and time you spend learning about him really lets you get invested and concerned for his well being. One of the last few chapters made me so happy for him that I started crying. I have only ever cried from happiness on one other occasion in my life, so this wasn't something that happens all the time for me. What other books have affected you in a similar manner?