What is it about uncles? They're always kind of funny and goofy. Even though Uncle Sam has his job, his home, and his freedom taken away from him, he never seems sad. Even though he dies a few pages into the novel, we get to know him as a diligent fisherman and boat builder who never let even the worst of situations get him down.
"'Umi no yo,' Uncle says, pointing to the grass. 'It's like the sea'" (1.4). These are the first words that we hear Uncle Sam say, and they're also the words that end the book. What you have to remember is that he's saying this about the tiniest trickle of a river in a valley in the middle of the prairies in British Columbia. In other words basically the furthest place you could be from the sea. That just shows you how much he misses it.
Uncle Sam's story is also the story of a huge community of Japanese fishermen who had their livelihoods taken away from them and were sent to places like Granton. Not only was he banned from being a fisherman, but to add insult to injury, his handcrafted boat was taken away from him. How messed up is this:
It wasn't a fishing vessel or an ordinary yacht, but a sleek boat designed by Father, made over many years and many winter evenings. A work of art. "What a beauty," the RCMP officer said in 1941 when he saw it. He shouted as he sliced back through the wake, "What a beauty! What a beauty!" (4.28)
Unfortunately, the boat isn't the only thing that was confiscated.
Just like many Japanese Canadian men, Uncle was also confiscated. Naomi says:
He had no provisions, nor did he have any idea where the gunboats were herding him and the other Japanese fishermen in the impounded fishing fleet. (4.30)
Whole communities lost their men along with their boats, and Uncle Sam represents them in Obasan.
Despite all of these sad times, Uncle isn't sad. It's not surprising, since his name (Isamu) means to cheer up or make happy. That's exactly what he does.
Think about his famous stone bread. Naomi says that it's so hard because he doesn't know how to bake properly, but stone bread has traditionally been a food made by people who have nothing else to eat. That's why he keeps adding random things to it:
Uncle had baked the bread too long. I refused to eat it, but Uncle kept making it that way over the years, "improving" the recipe with leftover oatmeal and barley. Sometimes he even added carrots and potatoes. But no matter what he put in it, it always ended up like a lump of granite on the counter. (3.26)
The stone bread is just an example of how Uncle tries to make the best out of even terrible situations.