At the tail-end of 1930 the Patersons set sail aboard the SS Mauritania bound for America, where Alec was to spend four months inspecting the penal and reformatory institutions of the United States. He was the first of his office to visit that country since Ruggles-Brise in 1897. The trustees of Rockefeller's Bureau of Social Hygiene made it possible, but it was Edward Cass, the general-secretary of the American Prison Association, and Sanford Bates, the first director of the recently formed Federal Bureau of Prisons, who planned his tour. Both hosts had adversely compared the rising crime and incarceration rate in America with ‘England's emptying prisons’, and hoped that Paterson's incursion would be the catalyst needed to change public and political opinion in the United States, and inspire a different approach to criminal justice.

On the week-long voyage to New York Alec had done his homework, reading various reports as well as Charles Dickens's American Notes. During his stay he too would take copious notes of all he saw and heard. They would become the factual basis of what he would write, which would be more an extended essay than a civil servant's report.

He gave a copy of The Prison Problem of America to his sister, who had ‘made possible this journey to a strange place’ (presumably by subsidising it financially as expenses never covered Alec's costs), and another to his wife, on which he had inscribed ‘To Frank, the best fellow-traveller in a big world’. She would accompany him on many of his trips, thus resolving in part the conflict of loyalties between service and family. But only in part, for as a result of these conjugal excursions their only child, Margaret, from her earliest years would be sent off to stay with Aunt Dodo in Bowdon or with Uncle Willis at his holiday home in Wales. She was the infant and adolescent casualty of their marital collaboration.