Answer: Child labour during the Industrial Revolution.
Step-by-step explanation:
This photograph is part of a historical source that proves child labour during the Industrial Revolution. The picture shows an underage girl in an industrial plant for the production and packaging of milk. This source is part of a wealth of evidence showing children's representation during the early Industrial Revolution. Child labour was present in Europe and America alike. The children worked for 12 hours in difficult conditions. The picture does not show the difficult conditions in which the children worked. Such a performance is not possible in the modern world, not in civilized and democratic societies. Namely, many international conventions do not allow minors to work in industrial plants.