There was a certain irony in the determination of immigration authorities and aroused citizens of the early twentieth century to turn back immigrants at Ellis Island on account of the eye disease, trachoma. It was true that many Germans from Russia and others arrived with telltale granules of the disease under their eyelids. But it was also true that trachoma was already established extensively in the United States. It could not be kept out. There is no reason to think trachoma had not been present here since the early days of the republic — at least ever since Napoleon’s woebegone soldiers, shielding their diseased eyes from the sun, returned from the Nile in 1801.