The Sins of the Father by Jeffrey Archer

On arrival in America, Harry Clifton is arrested for first degree murder, for killing Bill Bradshaw. He is tried, found guilty, and sentenced to death by the electric chair. Meanwhile Emma goes to London to give birth to Sebastian, Harry's child. On visiting Maisie to introduce her to her grandson, she becomes convinced that Harry is still alive. With the help of Sir Walter, she goes to America in search of Harry, where she must then fight to save his life. Meanwhile, when Sir Walter dies, Hugo takes over the Barrington shipping line, but manages to run the company into the ground, and when war is declared, Giles Barrington leaves Oxford to join the Gloucestershire Regiment, gaining respect and eventually glory in the military. And as the war progresses, Sebastian is brought up by his grandmother, Elizabeth Barrington. As a young man, he falls in love with the sister of a school friend, whose father is an Argentinean businessman who has made a fortune in arms dealing to both sides during the war.