Hally's memories of childhood are pretty bleak. He's clear on how unhappy his home life was and how much he hated living at his parents' boarding house. But he does have one happy memory that shows up during the play: flying a kite. Sam made Hally a kite out of scraps and trash. Hally couldn't believe it—what would a black man know about building a kite?
HALLY. Tomato-box wood and brown paper! Flour and water for glue! Two of my mother's old stockings for a tail, and then all those bits and pieces of string you made me tie together so that we could fly it! Hell, no, that was now only asking for a miracle to happen. (341-346)
The poor, homemade kite embarrassed Hally at the time; he was hoping no one would see him and Sam carrying the kite. The thing is, it did fly. This memory is important in Hally's life because it showed him that every now and then, against all probabilities, something good can happen:
HALLY. I was so proud of us! It was the most splendid thing I had ever seen. I wished there were hundreds of kids around to watch us. (874-876)
From shame to pride, all because of a kite. Sam's idea worked. But there's a foreshadowing in the kite story, too:
HALLY. It was sort of sad bringing it down, Sam. And it looked sad again when it was lying there on the ground. Like something that had lost its soul. (891-893)
Hmmm. Who's gonna lose his soul?
Later on in the play it comes out that Sam had made the kite because Hally felt so much shame about his alcoholic father. Sam tells him:
You hadn't done anything wrong, but you went around as if you owed the world an apology for being alive. I didn't like seeing that! That's not the way a boy grows up to be a man! … [. . .] If you really want to know, that's why I made you that kite. I wanted you to look up, be proud of something, of yourself… (Bitter smile at the memory) … and you certainly were that when I left you with it up there on the hill. (1833-1842)
Hally's shame is inherited; he feels embarrassed and guilty for his father's actions. Sam uses the kite to give him hope—something to "look up" to. It's a nice image for thinking about a positive future – high in the sky, soaring above but still connected to the ground. You could think of the kite as Sam's wish for South Africa's future, too—that Hally's generation would transform their inherited system of apartheid into an egalitarian society.