Systemic brokenness and disenfranchisement
One function of satire in general is to criticize society and social norms. This novel is certainly no exception, criticizing America and Canada from several points of view. The first and most glaringly obvious is the fact that Raven is an escaped slave in the Civil War. But, there are more nuanced criticisms than this, like when Lincoln's role as a politician clouds his role as moral leader (he allies himself with Swille for money). Then there is Yankee Jack, a despicable capitalist, but of the Northern variety. Instead of plantations and slaves, Yankee Jack uses unbridled capitalism to feed his hunger for power. In all places, in all times in the novel, Raven is shown the brokenness of his society. Because the novel is anachronistic, the effect is that the criticism is still current.
Satire and comedy
There are many jokes in the novel, such as the random shoutouts to present day technology. In fact, the novel's title Flight to Canada is a joke, because there were no planes in 1860's America, but in the novel, that doesn't stop Raven from fleeing slavery on a plane. The use of these comedic devices points to the ironic role of the novel as a social commentary. By using strange juxtapositions and 'bait-and-switches,' the novelist both lightens the mood, and he disarms the reader by amusing them. Another blackly humorous moment comes when Raven witnesses Lincoln's assassination on television, way before the television was invented.
Escape, adventure, and pursuit
The novel has a sort of cops-and-robbers feel to it, since during this time in America, slaves who escaped to the North were allowed to be captured and returned to the South. That's why Raven needs to make it all the way to Canada to be safe. The effect is that much of the novel involves chase sequences where Swille's men attempt to capture Raven.
