The River Between Us opens in the summer of 1916, in St. Louis, Missouri, where 15-year-old Howard Leland Hutchings narrates and is preparing to travel with his father to visit his father’s family in Grand Tower, Illinois. All Howard knows about his father’s family is that they lived through the Civil War. He can’t fathom being old enough to have voted for President Lincoln.

Howard’s father, the second William Hutchings, is a well-respected doctor. He is a busy man who works six-and-one-half days per week. However, he realizes that the US is likely to get involved in the Great War soon, so this may be his last opportunity to visit his parents. Therefore, Howard and his twin brothers, Raymond and Earl, get to drive across state lines in the family’s Model T Ford Touring Car to meet their distant grandparents.

Though Howard’s mother doesn’t approve of the trip, Howard is thrilled. He and his father have been prepping for days, making sure they have all the tools they might need and extra gasoline and filing down the spark plugs. Finally, the day of departure arrives. The boys wave goodbye to their mother and begin their road trip.