The exchange between America and Europe
One of the most important indicators of the meaning of a book is its title. This title, TransAtlantic is a reflection of the main theme, that throughout history, America has been connected to Europe culturally and economically, but that through recent history, the last 200 years or so, say, the rise of technology has made the populace more aware of that connection.
Technology and globalization
The effects of human technology are truly incredible. We get in planes and fly all the time, and most people have flown in an airplane—but it's still a miracle to fly. The book paints a beautiful, compelling picture of how technology and globalization are connected. In the same way that cars and roads mean that we can travel further and faster than ever before, so also the miracle of flight means that now people can travel without having to be on a boat. Therefore, people can connect to other cultures and other people more easily as technology improves.
Slavery and violence
When Lily Duggan decides to travel across the pond for a better life in America, she's liable to be disappointed. Although Frederick Douglass is a wonderful man, his popularity was due to how controversial slavery was at the time. That means that Lily is going to get away from Ireland, sure, but she's going to be in America for the Civil War. This shows that evil is also globalized, and you never can quite get away from hatred, no matter what nation you're in.
Immigration
In some lives, it becomes necessary to abandon your life and go to a new nation to seek a better one. This theme is shown beautifully through Lily's brave, but questionable decision to stowaway to America. That doesn't mean it's wrong to immigrate, by the way. It's just very difficult to gain citizenship and establish a working relationship with society as a foreigner. This is an important focal point, because technological advance implies easier, more efficient ways to immigrate.
