Yvonne Sylvain worked a few streets from where the baby was found

Yvonne Sylvain was a physician, one of the Sylvain sisters, and a member of the Ligue Feminine d'Action Sociale. She did not begin her one day a week at the general hospital in Port-au-Prince until several months after the newborn was found at LaSaline. She was already working close by, at Le Service d'Hygiene au Centre de Sante, whose district covered LaSaline and Cite Vincent. The details of the rescue would have come to her there. Sanders Johnson puts the two facts beside each other to close a distance readers tend to assume was wide. The League is usually described as an organisation of lettered, French speaking women of the capital's elite, several removes from the settlements by the water. In this instance the removes amounted to a few city blocks. The doctor compiling public health figures on infant mortality and the mother who left a child near the shore were using the same clinic, the same road, the same town.

Nigeria was a large territory with deeper internal divisions than any other British holding in West Africa. Its north and south had been governed separately until 1946. The north was mostly Muslim with old links across the Sahara to North Africa, the south heavily Christian after a long history of dealing with Europeans. Within the south, the Yoruba of the west and the Igbo of the east competed hard with each other. Within the north the argument was about the power of the aristocracy. From 1944 nationalist demands were carried by the National Council of Nigeria and the Cameroons, which the newspaper editor Nnamdi Azikiwe helped found and meant to be genuinely national. It was read instead as an Igbo vehicle, and it never united the country behind it. By the early 1950s the fear of Igbo dominance in British run elections had produced two rivals, the Northern People's Congress, largely Hausa and Fulani, and the Yoruba Action Group. A colony assembled for administrative convenience was proving impossible to convert into one nation.

The Société Haïtienne-Américaine de Développement Agricole was set up to grow rubber for a wartime market, and its method was to take farmland out of food. Crews cleared standing crops and cut down trees that bore fruit so that rubber could be planted in their place. Peasant families were moved off the plots they worked. The returns came in slowly and small. What the project delivered instead was displacement on a mass scale and the loss of the fruit-bearing stock that households had eaten from for generations. Fruit trees take years to bear. A family that loses one loses a decade of food, not a season of it. The rubber that replaced them failed to take hold, so the cleared ground gave nothing back to anybody. The ecological damage and the human damage were the same damage counted twice, and both were charged to people who had not asked for the scheme and could not refuse it.

In 1938 the anthropologist Jose Imbelloni proposed that the native people of the West Indies formed a distinct race, which he called Amazonid, and traced their biological descent from the Amazon basin, north through the Orinoco valley, and out along the island chain. The route is roughly right. Archaeology has since confirmed that direction of settlement, with pottery, languages and crops moving up the Antilles from the South American mainland. The racial classification is the part that has gone. Imbelloni belonged to a school that sorted humanity into fixed biological types with measurable skulls and firm edges, and running that machinery over the Caribbean produced a category nobody uses now. I keep it on a Haitian timeline for what it shows about the period. In 1938 a sound migration history and a false science of race arrived in the same sentence, and a reader had no easy way to take the one without the other.